I added a few pages to #Griffe's docs: alternative projects, downstream projects, and built-in/official/third-party extensions.

Very cool projects mentioned in there! #Docspec, #pdoc, #papyri, #quartodoc, etc. And I discovered a few Griffe extensions in the process, it's awesome 🤩

- https://mkdocstrings.github.io/griffe/alternatives/
- https://mkdocstrings.github.io/griffe/downstream-projects/
- https://mkdocstrings.github.io/griffe/extensions/built-in/