Improve documentation templates

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/168231



Merged-by: Diana Logan <dlogan@gitlab.com>
Approved-by: Diana Logan <dlogan@gitlab.com>
Reviewed-by: Diana Logan <dlogan@gitlab.com>
Co-authored-by: Marcin Sedlak-Jakubowski <msedlakjakubowski@gitlab.com>