Add BSR plugin for Rust

[stabai]

The Rust documentation site has info on how to install protoc-gen-rust. Essentially, looks like it can be done like this:

cargo install protobuf-codegen

I'm not certain if this is all that would be needed to build the plugin for BSR hosting, but just wanted to make sure you're aware of it.

[amckinney]

We discussed this at length in Slack here.

TL;DR -

Rust in general moves pretty fast, the tonic/axum/tower/ world also moves pretty fast, and we’re not aware of any Rust protobuf implementation that’s both (1) structured as a protoc plugin and (2) won significant mindshare. Until something emerges, we’re not the right folks to pick a winner there.

I'll leave this open because we'd eventually love to host a standard Rust plugin in the BSR, but it could be a while before this becomes a reality.

[stabai]

Also worth calling out the info provided in Luis' thread for an unofficial solution. Specifically, they have a plugin for Tonic at https://buf.build/prost/plugins

[bufdev]

See https://buf.build/plugins for all publicly-available plugins (which now includes Prost).