The documentation renderer based on sbt-paradox.
Since it's not supported anymore I decided to migrate it to scala 2.13 and improve by adding new directives.
pwd is hydro-serving-protos repository
docker run -it --entrypoint bash \
-v $(pwd)/doc:/out \
-v $(pwd)/src/:/protos \
pseudomuto/protoc-gen-doc
protoc --doc_out=/out --doc_opt=json,docs.json:hydro_serving_grpc/onnx/ $(find . -name '*.proto') 2> /out/warnings.txt