doc: Update Protobuf verification docswc-proto-contrib

The 'Contributing' section of the Protobuf doc still references the old
`gitaly-proto` project and incorrectly suggests that the source files
generated by `protoc` may vary with Go version.

This removes the outdated and incorrect information and adds a new
section with details on the `make` targets for linting and validating
protos.

1 files changed, 7 insertions, 12 deletions

diff --git a/doc/protobuf.md b/doc/protobuf.md
index f7e188323..4ed62296f 100644
--- a/doc/protobuf.md
+++ b/doc/protobuf.md
@@ -358,18 +358,6 @@ declared. This is done via the `go_package` option:
 
 This allows other protobuf files to locate and import the Go generated stubs.
 
-## Contributing
-
-The CI at https://gitlab.com/gitlab-org/gitaly-proto regenerates the
-client libraries to guard against the mistake of updating the .proto
-files but not the client libraries. This check uses `git diff` to look
-for changes. Some of the code in the Go client libraries is sensitive
-to implementation details of the Go standard library (specifically,
-the output of gzip). **Use the same Go version as .gitlab-ci.yml (Go
-1.13)** when generating new client libraries for a merge request.
-
-[DCO + License](CONTRIBUTING.md)
-
 ## Workflows
 
 ### Generating Protobuf sources
@@ -382,6 +370,13 @@ libraries before committing your change.
 make proto
 ```
 
+### Verifying Protobuf definitions
+
+Gitaly provides a `make lint-proto` target to verify that Protobuf definitions
+conform to our coding style. Furthermore, Gitaly's CI verifies that sources
+generated from the definitions are up-to-date by regenerating sources and then
+running `no-proto-changes`.
+
 ### Deprecating an RPC call
 
 See [PROCESS.md](PROCESS.md#rpc-deprecation-process).