Explain new contributer workflow
But from #5694 (closed) it's clear that it should be expanded (and I can remember that I also had trouble finding my way at first).
We could add a section like the one below in CONTRIBUTING.md and link it on https://www.ispconfig.org/development/. The 'How to start developing ISPConfig' link there leads to an old forum thread which should be integrated into CONTRIBUTING.md.
# Where to contribute? The best place to help with code is on https://git.ispconfig.org/ispconfig/ispconfig3/ there we work on issues and you can submit merge requests. To be able to submit a merge request you do need a fork of the repo though, please sent an email to firstname.lastname@example.org with your username, then you will receive rights to create your own project.