DM-36190: Enable additional features and configurations for user guides

[jonathansick]

More features for Rubin user guides:

• Code cells now include a copy button
• Pages now feature a link to edit the source on GitHub (the github repo can be automatically detected from pyproject.toml metadata and the path of the docs directory relative to the repository root is discovered with GitPython).
• More configurations available through documenteer.toml, rather than conf.py
  • disabling primary side bars on certain pages
  • setting the Python API content directory for autoodapi
  • setting the number header links to show in the nav bar