Adds CI to restrict types in a file (#24694)

* LETS GAMBLE!

* oops

* even more oops

* alright lets fuckin do it

* real names please

* comment

* Contributing.md update

* maybe someone will find this todo

* actually lets make it a define so people can't mistype it

* review

* changes

.github/workflows/ci.yml

@@ -48,6 +48,7 @@ jobs:
           python tools/ci/unticked_files.py ${GITHUB_WORKSPACE}
           python tools/ci/illegal_dme_files.py ${GITHUB_WORKSPACE}
           python tools/ci/define_sanity.py
+          python tools/ci/restrict_file_types.py
           python -m tools.ci.check_icon_conflicts
           python -m tools.ci.check_icon_dupenames
           python -m tools.maplint.source --github