Add syntax highlighting for TOML to rustdoc

[IvanUkhov]

Since TOML is such an essential part of the Rust ecosystem, it’s probably worth adding syntax highlighting for this file format. Here is an example of a code block that is currently ignored, syntax-highlighting-wise, when generating the documentation.

[GuillaumeGomez]

I'm shared on this. I agree on the fact that's nice to have and all, but that's not really useful in itself... Let's say I'm slightly against it but not much.

[steveklabnik]

I use it in the book, so 👍 from me.

[clux]

Maybe there's an easy way to optionally include a standard syntax highlighting js library for non-rust languages?

Highlighting other languages in rustdoc has been reasonably requested before: #40301

[JelteF]

I would really like this too.

[GuillaumeGomez]

@clux: you can add your own JS lib. A good example is this crate.

[camelid]

YAML support might also be nice, e.g. for clap.

[Kixunil]

I'd definitely like supporting other languages. Rust doesn't exist in a vacuum and there are plenty of reasons to write code in other langs, such as:

• bindings to other languages
• examples how to run a Rust application from a shell script
• references to foreign code ("this is equivalent to ... in C++")

[tyhdefu]

Interestingly enough, docs.rs does support highliting toml, if you navigate to crate (and the toml is there)
https://docs.rs/crate/rnotify/0.1.3