Give user option to use non-Exit Guards only
Bridges is absolute right way to solve such requests, but could be overkill solution.
To upload designs, you'll need to enable LFS and have admin enable hashed storage. More information
GitLab is used only for code review, issue tracking and project management. Canonical locations for source code are still https://gitweb.torproject.org/ https://git.torproject.org/ and git-rw.torproject.org.
Bridges is absolute right way to solve such requests, but could be overkill solution.