Add exceptions for docs branches

This adds exceptions to all the jobs that are running for docs changes, but should not. If a branch is pushed that uses the docs branch naming convention it will only run danger and docs-lint tests.

This is the current system for gitlab-ce, runner and omnibus pipelines, so now we can use the docs branch naming for all 4 main repos that we pull in docs from.

Tested with bab39f1c which shows the simplified CI pipeline.