Clean all type hints/docstrings

[jared321]

PR #19 is large. To ensure a good review of that and in light of the fact that we have not yet converged on rules for type hinting and Sphinx docstring formatting, reviewing type hints and docstrings in that PR are taking a back seat. Specifically, we will allow incorrect type hints and docstrings to make it into main.

After finishing the design work mentioned in Issue #29, we will need a campaign to update the type hints and docstrings to be correct and adhere to design goals. This should also include ensuring that all docs are using the appropriate Sphinx-based macros.

[beykyle]

Per @jared321 on slack, some API docstrings are rendered wrong by sphinx:

There were lots of rendering errors for these two routines and it took me some time to figure out to make Sphinx happy for > this google style input.

Note that the result
https://bfrescox--19.org.readthedocs.build/en/19/api.html#template-generation
looks much cleaner, normal, and consistent than what we have in other places
https://bfrescox--19.org.readthedocs.build/en/19/api.html#bfrescox.parse_performance_results