[Chapel Merge] Include protobuf implementation module in document

Branch: refs/heads/main
Revision: e4b8678
Author: lydia-duncan
Link: Unavailable
Log Message:

Merge pull request #19855 from lydia-duncan/docMissingPackages

Include protobuf implementation module in documented package modules
[reviewed by @dlongnecke-cray]

When we were organizing the package module documentation, I noticed that
this package didn't have documentation generated for it. This adds it to the
docs hierarchy.

Mostly just points to Protobuf documentation in Tools header.

Double-checked the links in the built documentation.

Modified Files:
M doc/rst/meta/modules/packages.rst

M modules/Makefile
M modules/packages/ProtobufProtocolSupport.chpl

Compare: https://github.com/chapel-lang/chapel/compare/7e5789185056...e4b867886f23