setup doxygen documentation

[BeastyBlacksmith]

This PR uses doxygen for the documentation. I found setup easier and results nicer than using sphinx (#20).

Docstrings need to formatted according to the specification (https://www.doxygen.nl/manual/docblocks.html#pythonblocks). The list of commands: https://www.doxygen.nl/manual/commands.html

• [x] setup action to build and deploy documentation
• [x] reformat docstrings (I did put stuff I didn't found an equivalent in html comments)

All in all its still a bit cluttered, but that could be improved in a different PR.

To build the documentation locally:

• install doxygen
• checkout this branch
• go to the docs directory
• run doxygen Doxyfile
• open docs/_build/html/index.html

Closes #17

[dwoschee]

Why isn’t PYTHON_DOCSTRING set to NO?

According to the docs, this would allow for more pythonic docstrings (at least omitting the ! at the beginning of each docstring). This sounds like a cleaner solution.

[BeastyBlacksmith]

Good point, I think I wanted to play safe

[BeastyBlacksmith]

Now I know, the system installed doxygen 1.8.17 and the documentation is for 1.9.2 ^^

[dwoschee]

PYTHON_DOCSTRING is introduced by doxygen 1.8.20. Would it be possible to use at least this version?

[BeastyBlacksmith]

I built version 1.9.1 from source, we might need to create an artifact for that in the github action though

[BeastyBlacksmith]

updated the configuration file and dropped the bangs