Add danger tooling for GLFM specification files

- All are backend+frontend, except the prosemirror
  json file, which is frontend only

spec/tooling/danger/project_helper_spec.rb

@@ -31,6 +31,8 @@
     end
 
     where(:path, :expected_categories) do
+      'glfm_specification/example_snapshots/prosemirror_json.yml' | [:frontend]
+      'glfm_specification/input/glfm_anything.yml' | [:frontend, :backend]
       'usage_data.rb'   | [:database, :backend, :product_intelligence]
       'doc/foo.md'      | [:docs]
       'CONTRIBUTING.md' | [:docs]

tooling/danger/project_helper.rb

@@ -17,6 +17,10 @@ module ProjectHelper
 
       # First-match win, so be sure to put more specific regex at the top...
       CATEGORIES = {
+        # GitLab Flavored Markdown Specification files. See more context at: https://docs.gitlab.com/ee/development/gitlab_flavored_markdown/specification_guide/#specification-files
+        %r{\Aglfm_specification/.+prosemirror_json\.yml} => [:frontend],
+        %r{\Aglfm_specification/.+\.yml} => [:frontend, :backend],
+
         [%r{usage_data\.rb}, %r{^(\+|-).*\s+(count|distinct_count|estimate_batch_distinct_count)\(.*\)(.*)$}] => [:database, :backend, :product_intelligence],
 
         %r{\A((ee|jh)/)?config/feature_flags/} => :feature_flag,