I'll definitely assert that Rust has nailed the automatic generation of documentation from comments in source code. It's a somewhat unusual language so getting used to how the docs are laid out toook a bit of time, but once I was using the language, the docs are the best I've ever used. Some examples:

https://docs.serde.rs/serde_json/

https://doc.rust-lang.org/std/vec/struct.Vec.html