stackoverflow.com/questions/14079655/cannot-get-toctree-in-sphinx-to-show-link
https://docs.readthedocs.io/en/stable/faq.html
https://www.sphinx-doc.org/en/1.8/usage/markdown.html
https://docs.readthedocs.io/en/stable/intro/getting-started-with-sphinx.html
https://www.docslikecode.com/articles/github-pages-python-sphinx/