Populate docstrs

[brews]

We have some docstr but they need to be properly populated in numpydoc style.

Need examples and "Also See" sections.

[brews]

Should check and see how the "Examples" sections in docstrings are:

• Rendered in API docs.
• Run and checked in pytest-docs

[brews]

Should check and see how the "Examples" sections in docstrings are:

• Rendered in API docs.
• Run and checked in pytest-docs

These seem to run fine. Some limitations. I can't get "See Also" to automatically link to relevant parts of the API reference.

Resources for later:

• https://numpydoc.readthedocs.io/
• https://mkdocstrings.github.io/griffe/reference/docstrings/#numpydoc-section-modules

Remember that the summary and extended summary should focus on functionality. Use "note" section to get into design etc.