Gitlab Service Desk for user support

Right now we are using RT for any user support. @gus and sometimes other contributors are replying to questions there and submitting issues in Gitlab when needed. We are discussing if it would makes sense to move that service to gitlab.

In gitlab we have the 'Service Desk' feature for issues in a project, where people can create issues and interact with their issue via email. Each issue gets created as confidential when people send a mail to the issue tracker for a project. We could have a project "frontdesk" or "support" where people create issues in and we triage them from there, moving them to the right project if it makes sense.

Example: https://gitlab.torproject.org/tpo/community/support/-/issues/40003

For it to be useful we would need:

• a way to have templates of common answers that we can apply for an issue.
• simple aliases to the project's email that people can use to send their first support's email.