to make it easier for devs to find the right place for code
close#655
Co-authored-by: Anbraten <anton@ju60.de>
Co-authored-by: qwerty287 <80460567+qwerty287@users.noreply.github.com>
- migrate step conditions back into pipeline syntax, but show 2-4 level in toc to be able to see `when` keywords
- create new backend section in admin docs
- update docusaurus
- remove prefix docker of container / container-image where possible
- replace terms SCM, VCS, Github with [forge](https://en.wikipedia.org/wiki/Forge_(software))
- add darkmode favicon variant