Replace Sphinx with new Typo3 documentation variant

[markusweigelt]

Since the beginning of 2024 you can switch to the new, PHP-based reStructured Text rendering to try it out. The new rendering will become mandatory in August 2024.

https://docs.typo3.org/m/typo3/docs-how-to-document/main/en-us/Migration/Index.html

What does PR do?

• migrate legacy Sphinx to PHP based rendering
• adjust developer documentation
• remove legacy code and files
• GitHub workflow to check documentation files

More informations:
https://docs.typo3.org/other/t3docs/render-guides/main/en-us/Introduction/Index.html

[beatrycze-volk]

Small suggestion, use the Draft option if you have opened PR and then observed that there are still some missing parts or you want to included some changes. After you are done with changing, you mark the PR as ready for review :)

[markusweigelt]

Alright, that was an exception. I had adjusted the documentation generation for Kitodo.Presentation, and then I noticed a few more things. Actually, I was done. Next time, I'll use the Draft PR. ;)

[beatrycze-volk]

Congratulations on your first contribution to DFG Viewer! :)