Add field/message/service options support

[mwitkow]

In our proto files we make extensive use of option parameters on messages, fields and services, for example for https://github.com/grpc-ecosystem/grpc-gateway or https://github.com/mwitkow/go-proto-validators.

It would be fantastic if the custom moustache templates supported accessing options so we could, for example, list the RESTful URLs of our services.

[htdvisser]

I'll take this 👍 first part is in https://github.com/pseudomuto/protokit/pull/2

[dwo]

I've been trying to follow along in the protokit code, but just to make sure: would this also make things like [deprecated=true] available to render in protoc-gen-doc?

[aSapien]

Hi, so Is there support for custom (user-provided) extensions/options for services and messages? I can't seem to land on the relevant doc and the templates wiki is marked "outdated".