devel/py-pdoc: Add py-pdoc 13.1.0

pdoc auto-generates API documentation that follows your project's Python module
hierarchy.

pdoc's main feature is a focus on simplicity: pdoc aims to do one thing and do
it well.

- Easy setup, no configuration necessary.
- Documentation is plain Markdown.
- First-class support for type annotations.
- Builtin web server with live reloading.
- Customizable HTML templates.
- Understands numpydoc and Google-style docstrings.