- In org mode you can specify an description for media via the following
syntax `[[description][media link]]`. The description is then used as
title or alt.
- This patch fixes the rendering of the description by seperating the
description and non-description cases and using `org.String()`.
- Added unit tests.
- Inspired by
6eb20dbda9/org/html_writer.go (L406-L427)
- Resolves https://codeberg.org/Codeberg/Community/issues/848

(cherry picked from commit 8b8aab8311)

Co-authored-by: Gusted <postmaster@gusted.xyz>

Fix #26367
Related #19745

Thanks @lazyky for providing  test cases

- Currently the post processing will transform all issue indexes (such as `#6`) into a clickable link.
- This makes sense in an situation like issues or PRs,
where referencing to other issues is quite common
and only referencing their issue index is an handy and efficient way to do it.
- Currently this is also run for documents
(which is the user profile and viewing rendered files),
but in those situations it's less common to reference issues by their index and instead could mean something else.
- This patch disables this post processing for issue index for documents. Matches Github's behavior.
- Added unit tests.
- Resolves https://codeberg.org/Codeberg/Community/issues/1120

Co-authored-by: Gusted <postmaster@gusted.xyz>

- The library that's being used for org-mode, [doesn't render the status
of list items](https://github.com/niklasfasching/go-org/issues/63).
- Add a modified version of the proposed CSS snippet to still display
the status for the list items. The alternative was parsing HTML and
transforming it, which is too complicated for this small task.
- Resolves https://codeberg.org/Codeberg/Community/issues/1099

(cherry picked from commit 9753c7e4b8)

Refs: https://codeberg.org/forgejo/forgejo/pulls/1071

Co-authored-by: Gusted <postmaster@gusted.xyz>

Regression: https://github.com/go-gitea/gitea/pull/24805
Closes: #25945

- Disallow `javascript`, `vbscript` and `data` (data uri images still
work) url schemes even if all other schemes are allowed
- Fixed older `cbthunderlink` tests

---------

Co-authored-by: delvh <dev.lh@web.de>

Result of running `perl -p -i -e 's#interface\{\}#any#g' **/*` and `make fmt`.

Basically the same [as golang did](2580d0e08d).

# The problem

There were many "path tricks":

* By default, Gitea uses its program directory as its work path
* Gitea tries to use the "work path" to guess its "custom path" and
"custom conf (app.ini)"
* Users might want to use other directories as work path
* The non-default work path should be passed to Gitea by GITEA_WORK_DIR
or "--work-path"
* But some Gitea processes are started without these values
    * The "serv" process started by OpenSSH server
    * The CLI sub-commands started by site admin
* The paths are guessed by SetCustomPathAndConf again and again
* The default values of "work path / custom path / custom conf" can be
changed when compiling

# The solution

* Use `InitWorkPathAndCommonConfig` to handle these path tricks, and use
test code to cover its behaviors.
* When Gitea's web server runs, write the WORK_PATH to "app.ini", this
value must be the most correct one, because if this value is not right,
users would find that the web UI doesn't work and then they should be
able to fix it.
* Then all other sub-commands can use the WORK_PATH in app.ini to
initialize their paths.
* By the way, when Gitea starts for git protocol, it shouldn't output
any log, otherwise the git protocol gets broken and client blocks
forever.

The "work path" priority is: WORK_PATH in app.ini > cmd arg --work-path
> env var GITEA_WORK_DIR > builtin default

The "app.ini" searching order is: cmd arg --config > cmd arg "work path
/ custom path" > env var "work path / custom path" > builtin default


## ⚠️ BREAKING

If your instance's "work path / custom path / custom conf" doesn't meet
the requirements (eg: work path must be absolute), Gitea will report a
fatal error and exit. You need to set these values according to the
error log.



----

Close #24818
Close #24222
Close #21606
Close #21498
Close #25107
Close #24981
Maybe close #24503

Replace #23301
Replace #22754

And maybe more

Fixes #25160.

`data-source-position` of checkboxes in a task list was incorrect
whenever there was YAML front matter. This would result in issue content
or PR descriptions getting corrupted with random `x` or space characters
when a user checked or unchecked a task.

This change makes the CSS for `<video>` in markup match that of `<img>`,
and also allows additional attributes to be used. This way the width,
padding, alignment should work equally well for both.

Support RTL content in Markdown:


![image](https://github.com/go-gitea/gitea/assets/115237/dedb1b0c-2f05-40dc-931a-0d9dc81f7c97)

Example document:
https://try.gitea.io/silverwind/symlink-test/src/branch/master/bidi-text.md
Same on GitHub:
https://github.com/silverwind/symlink-test/blob/master/bidi-text.md

`dir=auto` enables a browser heuristic that sets the text direction
automatically. It is the only way to get automatic text direction.

Ref: https://codeberg.org/Codeberg/Community/issues/1021

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

- Closes #21146
- Closes #16721

## :warning: BREAKING :warning:
This changes the default behavior to now create links for any URL scheme
when the user uses the markdown form for links (`[label](URL)`), this
doesn't affect the rendering of inline links. To opt-out set the
`markdown.CUSTOM_URL_SCHEMES` setting to a list of allowed schemes, all
other schemes (except `http` and `https`) won't be allowed.

# Before

![image](https://github.com/go-gitea/gitea/assets/20454870/35fa18ce-7dda-4995-b5b3-3f360f38296d)

# After

![image](https://github.com/go-gitea/gitea/assets/20454870/0922216b-0b35-4b77-9919-21a5c21dd5d0)

---------

Signed-off-by: Yarden Shoham <git@yardenshoham.com>
Co-authored-by: Giteabot <teabot@gitea.io>

This PR will merge 3 Init functions on setting packages as 1 and
introduce an options struct.

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Giteabot <teabot@gitea.io>

The old code has a lot of technical debts, eg: `repo/wiki/view.tmpl` /
`Iterate`

This PR improves the Wiki TOC display and improves the code.

---------

Co-authored-by: delvh <dev.lh@web.de>

Close #23671 

For the feature mentioned above, this PR append ' (comment)' to the
rendered html if it is a hashcomment.
After the PR, type in the following

```
pull request from other repo:
http://localhost:3000/testOrg/testOrgRepo/pulls/2

pull request from this repo:
http://localhost:3000/aaa/testA/pulls/2

issue comment from this repo:
http://localhost:3000/aaa/testA/issues/1#issuecomment-18

http://localhost:3000/aaa/testA/pulls/2#issue-9

issue comment from other repo:
http://localhost:3000/testOrg/testOrgRepo/pulls/2#issuecomment-24

http://localhost:3000/testOrg/testOrgRepo/pulls/2#issue
```
Gives:
<img width="687" alt="截屏2023-03-27 13 53 06"
src="https://user-images.githubusercontent.com/17645053/227852387-2b218e0d-3468-4d90-ad81-d702ddd17fd2.png">



Other than the above feature, this PR also includes two other changes:

1 Right now, the render of links from file changed tab in pull request
might not be very proper, for example, if type in the following. (not
sure if this is an issue or design, if not an issue, I will revert the
changes). example on
[try.gitea.io](https://try.gitea.io/HesterG/testrepo/pulls/1)
```
https://try.gitea.io/HesterG/testrepo/pulls/1/files#issuecomment-162725
https://try.gitea.io/HesterG/testrepo/pulls/1/files
```
it will render the following 
<img width="899" alt="截屏2023-03-24 15 41 37"
src="https://user-images.githubusercontent.com/17645053/227456117-5eccedb7-9118-4540-929d-aee9a76de852.png">

In this PR, skip processing the link into a ref issue if it is a link
from files changed tab in pull request

After:
type in following
```
hash comment on files changed tab:
http://localhost:3000/testOrg/testOrgRepo/pulls/2/files#issuecomment-24

files changed link:
http://localhost:3000/testOrg/testOrgRepo/pulls/2/files
```
Gives

<img width="708" alt="截屏2023-03-27 22 09 02"
src="https://user-images.githubusercontent.com/17645053/227964273-5dc06c50-3713-489c-b05d-d95367d0ab0f.png">

2 Right now, after editing the comment area, there will not be tippys
attached to `ref-issue`; and no tippy attached on preview as well.
example:

https://user-images.githubusercontent.com/17645053/227850540-5ae34e2d-b1d7-4d0d-9726-7701bf825d1f.mov

In this PR, in frontend, make sure tippy is added after editing the
comment, and to the comment on preview tab
After:

https://user-images.githubusercontent.com/17645053/227853777-06f56b4c-1148-467c-b6f7-f79418e67504.mov

Remove `[repository.editor] PREVIEWABLE_FILE_MODES` setting that seemed
like it was intended to support this but did not work. Instead, whenever
viewing a file shows a preview, also have a Preview tab in the file
editor.

Add new `/markup` web and API endpoints with `comment`, `gfm`,
`markdown` and new `file` mode that uses a file path to determine the
renderer.

Remove `/markdown` web endpoint but keep the API for backwards and
GitHub compatibility.

## ⚠️ BREAKING ⚠️

The `[repository.editor] PREVIEWABLE_FILE_MODES` setting was removed.
This setting served no practical purpose and was not working correctly.
Instead a preview tab is always shown in the file editor when supported.

---------

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

This branch continues the work of #23092 and attempts to rid the
codebase of any `nil` contexts when using a `RenderContext`.

Anything that renders markdown or does post processing may call
`markup.sha1CurrentPatternProcessor()`, and this runs
`git.OpenRepository()`, which needs a context. It will panic if the
context is `nil`. This branch attempts to _always_ include a context
when creating a `RenderContext` to prevent future crashes.

Co-authored-by: Kyle D <kdumontnu@gmail.com>

As you can imagine, for the Blender development process it is rather
nice to be able to include videos in issues, pull requests, etc.

This PR allows the `<video>` HTML tag to be used in MarkDown, with the
`src`, `autoplay`, and `controls` attributes.

## Help Needed

To have this fully functional, personally I feel the following things
are still missing, and would appreciate some help from the Gitea team.

### Styling

Some CSS is needed, but I couldn't figure out which of the LESS files
would work. I tried `web_src/less/markup/content.less` and
`web_src/less/_base.less`, but after running `make` the changes weren't
seen in the frontend.

This I would consider a minimal set of CSS rules to be applied:

```css
video {
  max-width: 100%;
  max-height: 100vh;
}
```

### Default Attributes

It would be fantastic if Gitea could add some default attributes to the
`<video>` tag. Basically `controls` should always be there, as there is
no point in disallowing scrolling through videos, looping them, etc.

### Integration with the attachments system

Another thing that could be added, but probably should be done in a
separate PR, is the integration with the attachments system. Dragging in
a video should attach it, then generate the appropriate MarkDown/HTML.

Some bugs caused by less unit tests in fundamental packages. This PR
refactor `setting` package so that create a unit test will be easier
than before.

- All `LoadFromXXX` files has been splited as two functions, one is
`InitProviderFromXXX` and `LoadCommonSettings`. The first functions will
only include the code to create or new a ini file. The second function
will load common settings.
- It also renames all functions in setting from `newXXXService` to
`loadXXXSetting` or `loadXXXFrom` to make the function name less
confusing.
- Move `XORMLog` to `SQLLog` because it's a better name for that.

Maybe we should finally move these `loadXXXSetting` into the `XXXInit`
function? Any idea?

---------

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: delvh <dev.lh@web.de>

These functions don't examine contents, just filenames, so they don't
fit in well in a markup module.

This was originally part of
https://github.com/go-gitea/gitea/pull/22177.

Signed-off-by: Nick Guenther <nick.guenther@polymtl.ca>

Fixes anchored markup links by adding `user-content-` (which is
prepended to IDs)

Closes https://codeberg.org/Codeberg/Community/issues/894

Fixes #22628

This PR adds cross references for commits by using the format
`owner/repo@commit` . References are rendered like
[go-gitea/lgtm@6fe88302](#dummy).

---------

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

Support [asciicast
files](https://github.com/asciinema/asciinema/blob/develop/doc/asciicast-v2.md)
as a new markup via
[asciinema-player](https://github.com/asciinema/asciinema-player). For
more on asciinema, see the [introduction](https://asciinema.org/).

So users can use asciinema recorder to generate an asciicast file (or
you can download a sample file from
https://asciinema.org/a/335480.cast?dl=1), then upload it to Gitea and
play it on Gitea.

Snapshots:
<details>

## Upload asciicast files

<img width="1134" alt="image"
src="https://user-images.githubusercontent.com/9418365/212461061-cc2c7181-0e14-4534-af55-1ec60a639fd1.png">

## Open an asciicast file

<img width="1137" alt="image"
src="https://user-images.githubusercontent.com/9418365/212461090-a3b5141f-4894-430d-a2b4-ea257801a0ed.png">

## Play it

<img width="1144" alt="image"
src="https://user-images.githubusercontent.com/9418365/212461157-4e82db69-0e41-471d-928f-ac1fe0737105.png">

## Copy contents from the "video"

<img width="1145" alt="image"
src="https://user-images.githubusercontent.com/9418365/212461286-211612bc-15d6-427a-89a9-6abff5c6a0a5.png">


## View the source

<img width="1140" alt="image"
src="https://user-images.githubusercontent.com/9418365/212461187-05473b2d-ba3d-4072-84a6-4aa1e7d82182.png">


</details>

Known issue:

Don't support the [v1 version asciicast
files](https://github.com/asciinema/asciinema/blob/develop/doc/asciicast-v1.md),
it's a poorly designed version, it does not specify the file extension
and uses `*.json` usually, so it's impossible to recognize the files.

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

When using an external renderer, STDOUT is expected to be HTML. But
anything written to STDERR is currently ignored. In cases where the
renderer fails, I would like to log any error messages that the external
program outputs to STDERR.

- Remove code that isn't being used.

Found this is my stash from a few weeks ago, not sure how I found this
in the first place.

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

extract from #20326

Change all license headers to comply with REUSE specification.

Fix #16132

Co-authored-by: flynnnnnnnnnn <flynnnnnnnnnn@github>
Co-authored-by: John Olheiser <john.olheiser@gmail.com>

The [labels in issue YAML
templates](https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/syntax-for-issue-forms#top-level-syntax)
can be a string array or a comma-delimited string, so a single string
should be valid labels.

The old codes committed in #20987 ignore this, that's why the warning is
displayed:

<img width="618" alt="image"
src="https://user-images.githubusercontent.com/9418365/202112642-93dc72d0-71c3-40a2-9720-30fc2d48c97c.png">

Fixes #17877.

For each quote block, the first `**Note**` or `**Warning**` gets an icon
prepended to it and its text is colored accordingly. GitHub does this
(community/community#16925). [Initially requested on
Discord.](https://discord.com/channels/322538954119184384/322538954119184384/1038816475638661181)

### Before

![image](https://user-images.githubusercontent.com/20454870/200408558-bd318302-6ff9-4d56-996f-9190e89013ec.png)

### After

![image](https://user-images.githubusercontent.com/20454870/200658863-1bac6461-dae7-4bf2-abd2-672d209574e4.png)

Signed-off-by: Yarden Shoham <hrsi88@gmail.com>
Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: silverwind <me@silverwind.io>

Found using
`find . -type f -name '*.go' -print -exec vim {} -c
':%s/fmt\.Errorf(\(.*\)%v\(.*\)err/fmt.Errorf(\1%w\2err/g' -c ':wq' \;`

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

Previously mentioning a user would link to its profile, regardless of
whether the user existed. This change tests if the user exists and only
if it does - a link to its profile is added.

* Fixes #3444

Signed-off-by: Yarden Shoham <hrsi88@gmail.com>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

It distractingly shows up on unit tests

* Looks like a leftover from #20571

Signed-off-by: Yarden Shoham <hrsi88@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

* Resolves #3047

Every time a color code will be in \`backticks`, a cute little color
preview will pop up


[Inspiration](https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#supported-color-models)

#### Before

![image](https://user-images.githubusercontent.com/20454870/196631524-298afbbf-d2c8-4018-92a5-0393a693d850.png)

#### After

![image](https://user-images.githubusercontent.com/20454870/196631397-36c561e4-08f5-465a-a36e-76084e30b08a.png)

Signed-off-by: Yarden Shoham <hrsi88@gmail.com>
Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

This PR adds a generic set type to get rid of maps used as sets.

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

There is a small bug in #20571 whereby `$a a$b b$` will not be correctly
detected as a math inline block of `a a$b b`. This PR fixes this.

Also reenable test cases as per #21340 

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

The behaviour of `PreventSurroundingPre` has changed in
https://github.com/alecthomas/chroma/pull/618 so that apparently it now
causes line wrapper tags to be no longer emitted, but we need some form
of indication to split the HTML into lines, so I did what
https://github.com/yuin/goldmark-highlighting/pull/33 did and added the
`nopWrapper`.

Maybe there are more elegant solutions but for some reason, just
splitting the HTML string on `\n` did not work.

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

close #21176

This PR adds mathematical rendering with KaTeX.

The first step is to add a Goldmark extension that detects the latex
(and tex) mathematics delimiters.

The second step to make this extension only run if math support is
enabled.

The second step is to then add KaTeX CSS and JS to the head which will
load after the dom is rendered.

Fix #3445

Signed-off-by: Andrew Thornton <art27@cantab.net>

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

* Add initial playwright config

* Simplify Makefile

* Simplify Makefile

* Use correct config files

* Update playwright settings

* Fix package-lock file

* Don't use test logger for e2e tests

* fix frontend lint

* Allow passing TEST_LOGGER variable

* Init postgres database

* use standard gitea env variables

* Update playwright

* update drone

* Move empty env var to commands

* Cleanup

* Move integrations to subfolder

* tests integrations to tests integraton

* Run e2e tests with go test

* Fix linting

* install CI deps

* Add files to ESlint

* Fix drone typo

* Don't log to console in CI

* Use go test http server

* Add build step before tests

* Move shared init function to common package

* fix drone

* Clean up tests

* Fix linting

* Better mocking for page + version string

* Cleanup test generation

* Remove dependency on gitea binary

* Fix linting

* add initial support for running specific tests

* Add ACCEPT_VISUAL variable

* don't require git-lfs

* Add initial documentation

* Review feedback

* Add logged in session test

* Attempt fixing drone race

* Cleanup and bump version

* Bump deps

* Review feedback

* simplify installation

* Fix ci

* Update install docs

* feat: extend issue template for yaml

* feat: support yaml template

* feat: render form to markdown

* feat: support yaml template for pr

* chore: rename to Fields

* feat: template unmarshal

* feat: split template

* feat: render to markdown

* feat: use full name as template file name

* chore: remove useless file

* feat: use dropdown of fomantic ui

* feat: update input style

* docs: more comments

* fix: render text without render

* chore: fix lint error

* fix: support use description as about in markdown

* fix: add field class in form

* chore: generate swagger

* feat: validate template

* feat: support is_nummber and regex

* test: fix broken unit tests

* fix: ignore empty body of md template

* fix: make multiple easymde editors work in one page

* feat: better UI

* fix: js error in pr form

* chore: generate swagger

* feat: support regex validation

* chore: generate swagger

* fix: refresh each markdown editor

* chore: give up required validation

* fix: correct issue template candidates

* fix: correct checkboxes style

* chore: ignore .hugo_build.lock in docs

* docs: separate out a new doc for merge templates

* docs: introduce syntax of yaml template

* feat: show a alert for invalid templates

* test: add case for a valid template

* fix: correct attributes of required checkbox

* fix: add class not-under-easymde for dropzone

* fix: use more back-quotes

* chore: remove translation in zh-CN

* fix EasyMDE statusbar margin

* fix: remove repeated blocks

* fix: reuse regex for quotes

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

* 1.19 gofumpt

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Change CSV test

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Commit whitespace fixes from @zeripath

Co-authored-by: zeripath <art27@cantab.net>

* Update emoji

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* bump swagger & fix generate-swagger

Signed-off-by: jolheiser <john.olheiser@gmail.com>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Lauris BH <lauris@nix.lv>

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

* Support localized README

* Slightly simplify getting the readme file and add some tests. Ensure that i18n also
works for docs/ etc.

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Update modules/markup/renderer.go

* Update modules/markup/renderer.go

* Update modules/markup/renderer.go

Co-authored-by: Andrew Thornton <art27@cantab.net>

Use body text color in for links in the repository files table
Issue/PR links (`.ref-issue`) will not be affected, as seen in other git services.

Co-authored-by: silverwind <me@silverwind.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Lauris BH <lauris@nix.lv>

`<span style="color: red">Hello World!</span>` will now be accepted by
Bluemonday, other properties are still disallowed by Bluemonday.

- This code is only valid when `refNumeric` exist(otherwise we didn't find
such numeric PR and can skip that check) and give a free-pas to the  "BEFORE" check when
`ref` is nil.
- Resolves #20109

* Prototyping

* Start work on creating offsets

* Modify tests

* Start prototyping with actual MPH

* Twiddle around

* Twiddle around comments

* Convert templates

* Fix external languages

* Fix latest translation

* Fix some test

* Tidy up code

* Use simple map

* go mod tidy

* Move back to data structure

- Uses less memory by creating for each language a map.

* Apply suggestions from code review

Co-authored-by: delvh <dev.lh@web.de>

* Add some comments

* Fix tests

* Try to fix tests

* Use en-US as defacto fallback

* Use correct slices

* refactor (#4)

* Remove TryTr, add log for missing translation key

* Refactor i18n

- Separate dev and production locale stores.
- Allow for live-reloading in dev mode.

Co-authored-by: zeripath <art27@cantab.net>

* Fix live-reloading & check for errors

* Make linter happy

* live-reload with periodic check (#5)

* Fix tests

Co-authored-by: delvh <dev.lh@web.de>
Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: zeripath <art27@cantab.net>

Add nakedret, unconvert, wastedassign, stylecheck and nolintlint linters to improve code readability

- nakedret - https://github.com/alexkohler/nakedret - nakedret is a Go static analysis tool to find naked returns in functions greater than a specified function length.
- unconvert - https://github.com/mdempsky/unconvert - Remove unnecessary type conversions
- wastedassign - https://github.com/sanposhiho/wastedassign -  wastedassign finds wasted assignment statements.
- notlintlint -  Reports ill-formed or insufficient nolint directives
- stylecheck - https://staticcheck.io/docs/checks/#ST - keep style consistent
  - excluded: [ST1003 - Poorly chosen identifier](https://staticcheck.io/docs/checks/#ST1003) and [ST1005 - Incorrectly formatted error string](https://staticcheck.io/docs/checks/#ST1005)

* clean git support for ver < 2.0

* fine tune tests for markup (which requires git module)

* remove unnecessary comments

* try to fix tests

* try test again

* use const for GitVersionRequired instead of var

* try to fix integration test

* Refactor CheckAttributeReader to make a *git.Repository version

* update document for commit signing with Gitea's internal gitconfig

* update document for commit signing with Gitea's internal gitconfig

Co-authored-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>