Add support removable media for snap version of gitia.
for get more info about removable media interface see the snapcraft [documentation](https://snapcraft.io/docs/removable-media-interface)

* Consolidate Logos and update README header

- Remove unused `logo-lg.png`, `logo-sm.png` and `logo-192.png`.
- Consolidate `favicon.svg` and `logo.svg` to just `logo.svg`.
- Remove Safari Mask icon, it seems to work fine with just `favicon.png` (no SVG support).
- Remove Fluid Icon. It only served Firefox and SVG works just fine there.
- Update customization instructions.
- Update README.md to use SVG icon, increase logo size and center it and badges.

* Update README_ZH.md

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

* Update README_ZH.md

Co-authored-by: 6543 <6543@obermui.de>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>

* gitea png to logo.svg

* gitea safari svg to logo

* minify svgs

* Update english docs

* Update missing section on customizing logo

* Store repository data in data path if not previously set

* update docs

* Update docs/content/doc/advanced/config-cheat-sheet.en-us.md

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

* update docs

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

Signed-off-by: artivis <deray.jeremie@gmail.com>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

This adds some logic to enable the snapcraft builds of the gitea snap to create both builds of the latest tip of master for edge channels, and stable releases.

The logic simply looks for a new upstream release in github, and if that latest tagged release is not the same as the release in the candidate channel in the snap store, then it must be new, and so we checkout that tag and build that. If the current released tag is the same as what's in candidate, we build whatever is in git master.

The process for using this is:

Initially: When this lands, it will build the latest stable release of gitea and push to the edge channel in the snap store. Someone on the release team can go to https://snapcraft.io/gitea/releases and release that build to stable and candidate.

Ongoing: The next build to be triggered will be a git master build, and can just sit in edge, nothing for the release team to do.

On new release: The next build triggered will contain the stable release, and will be published to edge. Someone on the release team can login to the above URL and release that again to stable & candidate. Alternatively they can release to candidate, do some additional testing on that release before releasing to stable.

Hope that all makes sense. Questions / comments welcome.

I'm super keen to see stable releases of Gitea in the stable channel of the Snap Store. I'd like to promote it but I can't really until it's in stable.

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

Builds will fail on s390x, i386 and ppc64el because we depend on nodejs, which is only published for armhf, arm64 and amd64. This change merely tells the snap build farm to not waste time trying to build on architectures will will guarantee failure. Apologies for overlooking this in our previous PR.

Example build failures can be seen at [i386](https://launchpad.net/~build.snapcraft.io/+snap/53d5570c233b8b3663242f8d94dc21ad/+build/945935), [ppc64el](https://launchpad.net/~build.snapcraft.io/+snap/53d5570c233b8b3663242f8d94dc21ad/+build/945939), [s390x](https://launchpad.net/~build.snapcraft.io/+snap/53d5570c233b8b3663242f8d94dc21ad/+build/945940)

Removing some of the complexity, together with the install and
configure hook.

Signed-off-by: Sergio Schvezov <sergio.schvezov@canonical.com>

* 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

* use vfsgen instead of go-bindata

* fix templates

* fix fmt

* vendor vsfgen

* Modify tbraeutigam/gogs-snap for gitea

* Fix building on 16.04 (manually build go-bindata).
-> add _source.tar.bz2 to .gitignore (used by snapcraft cleanbuild)

* Streamline Snap packaging:
 - Take advantage of install-hooks (snapd 2.27)
 - Use snapctl configuration storage for unchanging values

* Move to using Snap Hooks for configuration

* Missed re-adding daemon statement

* Fix two warnings from Codacy.