Mkdocs has quite a good ecosysten especially around Mkdocs Material[0] used by projects like FastApi[1].

Mkdocs is quite easy to setup and has features comparable to Sphinx and MyST-Parse. Iirc it has less stuff out of the box compared to Sphinx but nakes up for it with a mature plugin ecosystem.

[0]: https://squidfunk.github.io/mkdocs-material/ [1]: https://fastapi.tiangolo.com/