* Add frontend/backend make targets, fix source release

- Add 'make backend' and 'make frontend' make targets which are used to
  build go and js/css/svg files respectively.

- The 'backend' target can be invoked without requiring Node.js to be
  present on the system if pre-built frontend assets are present like
  in the release source tarballs.

- Fix source releases missing 'dist' folders inside 'node_modules' which
  were erronously excluded from tar.

- Store VERSION in file VERSION for the release tarballs and prefer that
  file over git-derived version.

* fix release task

* fix typo

* fix another typo

Fixes: https://github.com/go-gitea/gitea/issues/10253

* Remove more explicit 'generate' calls

`generate` is now implicit during `build` since #9114, it is no longer
necessary or desired to specify it explicitely.

* add js,css,generate dependencies to release task

* remove generate warning as per @lunny

* add warnging on docs

* fix docs

- Added Node.js as build dependency and removes build files from git.
- Added version checks for both Go and Node.js.
- Overhauled the js/css make target to only run when needed.
- Merged the `generate` make target into `build` as per suggestion.

Fixes: https://github.com/go-gitea/gitea/issues/6782
Fixes: https://github.com/go-gitea/gitea/issues/9216

The current source docs reference AppWorkDir instead of AppWorkPath

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

* use vendors when go generate

* update docs about golang minimal requirement from 1.9 to 1.11

* fix build

* fix rel-ref

* fixup

* Update and expand building information

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

* remove extraneous extra line

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

* Fix spelling mistake

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

* Note about documentation for the website

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

* More changes

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

* Clarified the automatic build dependency

* Update the from-source to match the hacking information

* Extend quotes

* Update required go and discord link

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

* Update hacking-on-gitea.en-us.md

Add in information about postcss

* Remove tidb reference from docs

* Update from-source.fr-fr.md

* Update from-source.zh-cn.md

* Update from-source.zh-tw.md

* Update source installation requirements

We require Golang 1.8 since we use `net/url.PathEscape` which was not introduced until then

* Use Golang 1.8 for build and test

If we state Golang 1.8 we should test using that version as well

* Use golang 1.8 only for single build to see if everything compiles

* Change back edge also for commented out sqlite test

* Clean up spelling, grammar, perspective, whitespace, language, markup, etc.

* import docs into main repository

Signed-off-by: Matti Ranta <matti@mdranta.net>