Many Python tools and applications use a documentation generator called Sphinx to create their documentation. I recently discovered this for the first time when I was looking at Simon Willison's LLM tool on GitHub. Sphinx takes Markdown files and turns them into HTML files, making it easier to create nice-looking documentation websites. There are also a lot of plugins you can use to add extra features and capabilities to Sphinx.
I gave it a try and learned how to customize the fonts and CSS styles. Repo is here.