Clarify fetching TF templates

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/105284



Merged-by: Phillip Wells <pwells@gitlab.com>
Approved-by: Timo Furrer <tfurrer@gitlab.com>
Approved-by: Phillip Wells <pwells@gitlab.com>
Co-authored-by: João Alexandre Cunha <j.a.cunha@gmail.com>