Add textproc/py-sphinxcontrib-napoleon

Sphinx extension that parses both NumPy and Google style docstrings

Napoleon is a pre-processor that parses NumPy and Google style docstrings and
converts them to reStructuredText before Sphinx attempts to parse them. This
happens in an intermediate step while Sphinx is processing the documentation,
so it doesn't modify any of the docstrings in your actual source code files.

WWW: https://pypi.org/project/sphinxcontrib-napoleon/