Adds note to tw_onboarding template about permissions for the (new) handbook project.
This MR updates the tw_onboarding template with the following changes:
- removes the
handbook
project from the list of GitLab projects that require maintainer access. - adds a note to clarify why maintainer access is not required.
Relates to: !220 (comment 1635497161)
Edited by Lysanne Pinto