Update references to docs global nav file

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/183069



Merged-by: Suzanne Selhorn <sselhorn@gitlab.com>
Approved-by: Suzanne Selhorn <sselhorn@gitlab.com>
Reviewed-by: Sarah German <sgerman@gitlab.com>
Co-authored-by: Sarah German <sgerman@gitlab.com>