We recently did explore Phoenix as an inspiration, and we really liked how docs work in the Elixir ecosystem. We can't really copy everything, but we could copy e.g. automatic docs generation for the API (and JS/TS has solutions for that that even Phoenix uses e.g. https://hexdocs.pm/phoenix/js/index.html). I love the fact that API docs and code comments can't get out of sync that way.

Still parts of the docs have to be handmade, and those are usually not supported directly by the ecosystem, so you have to build your own solutions.