sphinx pythia theme

[negin513]

Since the update of sphinx pythia theme the page build has changed and possibly fail.

[kafitzgerald]

pinning to this version should help for the time being: https://github.com/ProjectPythia/sphinx-pythia-theme/releases/tag/2022.3.29

the recent releases had some pretty major changes.

[negin513]

Thanks @kafitzgerald . For now, I put in a quick fix: #25
It seems like, for the time being, it is working. I think with Python versions older than 3.7, it fails but should be fine for now. ;-)

[kafitzgerald]

We could also look at using something like the sphinx-book-theme that might be a little more robust.

This is a maybe next time around suggestion though.