Test autodoc2

[j-emberton]

Switch out autodoc for autodoc2 and evaluate any improvement to the docs build.

Review which currently used dependencies become deprecated through use of autodoc2

[MarionBWeinzierl]

Is this basically the differences we are looking at? https://sphinx-autodoc2.readthedocs.io/en/latest/autodoc_diff.html

[j-emberton]

yes I think so

[MarionBWeinzierl]

Hm, I am getting this error when setting
autodoc2_packages = [ "../../pyrealm" ]

[j-emberton]

Hm, I am getting this error when setting autodoc2_packages = [ "../../pyrealm" ]

That doesn't look good. I'm not sure I have much confidence in autodoc2. It seems a little abandoned. We could try posting an issue with this error to see if the lead dev responds, but I'm not hopeful.