* Rework 'make generate-images'
- Remove external dependencies and replace it with a node script that
does does the same.
- Move detail removal from gitea-sm.png to favicon.png
- Remove favicon.ico and its generation, it is unused and we already serve
favicon.png in its place.
Fixes: https://github.com/go-gitea/gitea/issues/12314
* use proper centering value for preserveAspectRatio
* fix lint
* use fabric
* better linting fix
* fix typo
* mention detail-remove class in docs
* Create manifest and serviceworker
* Create templates and add AppSubUrl
* Add JSRenderer
* fix ctx type
* Add JSRenderer to static.go
* Complete adding {{AppSubUrl}}
* Add more fonts to urlsToCache
* Add 512px and 192px icons
* Hardcode font MD5
* Default theme doesn't have a specific CSS file
