Map route to proto file

First of all, if this feature exists, consider this a possible documentation issue, as I did not know how to achive it.

All documentation and code examples assume the proto files are pre-existing.

I would like to follow a pattern where each service documents itself. I use the Reflection service to be able to hook up e.g. grpc-ui and grpcurl to my services. I would also like to be able to download the proto file from the service itself (over plain vanilla HTTP).

*Proposed solution*

Add an extension method, e.g. MapProtobufMetadata("/my-metadata-endpoint.proto"). This serves the combined .proto file for all defined service.
As an alternative e.g. MapProtobufMetadata"/my-metadata-endpoint/myservice.proto"). This serves the proto file for a specific service.

The only reason I could think of for not having this is that there is a better way to do it, but I really couldn't find one.