Resolve some docs warnings

[kurtmckee]

Pull Request check-list

Please make sure to review and check all of these items:

• Do tests and lints pass with this change?
• Do the CI tests pass with this change (enable it first in your forked repo and wait for the github action build to finish)?
• Is the new or changed code fully tested?
• Is a documentation update included (if this change modifies existing APIs, or introduces new ones)?
• Is there an example added to the examples folder (if applicable)?
• Was the change added to CHANGES file?

NOTE: these things are not required to open a PR and can be done
afterwards / while the PR is open.

Description of change

This PR begins to resolve the many warnings output during documentation builds (recent example on Read the Docs; expand the python -m sphinx ... log line to see the warnings and errors).

There are a significant number of rendering issues caused by incorrect Napoleon formatting in docstrings, but this PR is specifically aiming to resolve some warnings and errors. Here's an example of a rendering issue caused by incorrect Napoleon formatting that needs to be addressed: