Explore migration story from pydata-sphinx-theme

[pradyunsg]

This would likely involve providing a porting guide to users, documenting the process and the equivalents/alternatives for various knobs of the PyData Sphinx theme.

That theme provides a lot of configuration knobs -- https://pydata-sphinx-theme.readthedocs.io/en/stable/user_guide/configuring.html -- which is... a lot of surface area. :)

It also lets users customise the sections on the page, which... feels like a death sentence through backwards compatibility concerns (https://pydata-sphinx-theme.readthedocs.io/en/stable/user_guide/sections.html). It would make sense to explore whether the most popular projects that use that theme are actually using section customisation -- if they aren't, that's a strong reason to omit such customisation.