feat: add protobuf language support

[yusdacra]

• Add indents

NOTE: This only supports protobuf 3 syntax.

[archseer]

Any reason you chose that grammar instead of https://github.com/mitchellh/tree-sitter-proto ? I think it looks fine otherwise 👍🏻

[yusdacra]

Any reason you chose that grammar instead of mitchellh/tree-sitter-proto ? I think it looks fine otherwise 👍🏻

It's basically the same grammar, except the node names are camelCase, and some new grammar is added. I had started working on that so I continued working on it. (may be a good idea to upstream changes there in the future)

[archseer]

Merged!