Have a complete example with plugin compilation and generation

[remyleone]

We are considering migrating to bazel while still using buf. It would be helpful to have a full example that exposes how to compiles a protoc-gen plugin in go (using for instance gazelle and rules_go) and rules_buf to have a full generation example.
This would be really helpful to simplify our pipelines and enable all bazel and buf features combined.

Does rules_buf supports generation yet? Would you consider writing an example for it?