https://sphinxcontrib-napoleon.readthedocs.io/en/latest/exam...
Markdown has a lot of implementations (with some fragmentation, granted) and is adopted by many diverse projects outside the python sphere.
Pandoc supports rST.
I write Elixir docs on my projects because it's easy pretty and obsessively making my docs prettier hits that spot in my brain.
Extreme example:
https://hexdocs.pm/zigler/Zigler.html
Where I've automatically marshalled zig code into the elixir documentation (https://hexdocs.pm/zigler/beam.html#get_f32/2) and you can click the slash in the upper right of the function header to link to the code on Github.
As a bonus, check it out on mobile and compare it to this on mobile: