fixup! Adding issue and merge request templates

add rebase MR template

.gitlab/merge_request_templates/Rebase.md

+## Merge Info
+
+<!-- Bookkeeping information for release management -->
+
+### Rebase Issue
+- tor-browser#xxxxx
+- mullvad-browser#xxxxx
+
+### Release Prep Issue
+- tor-browser-build#xxxxx
+
+### Issue Tracking
+- [ ] Link rebase issue with appropriate [Release Prep issue](https://gitlab.torproject.org/groups/tpo/applications/-/issues/?sort=updated_desc&state=opened&label_name%5B%5D=Release%20Prep&first_page_size=20) for changelog generation
+
+### Review
+
+#### Request Reviewer
+
+- [ ] Request review from a release engineer: boklm, dan, ma1, morgan, pierov
+
+#### Change Description
+
+<!-- Any interesting notes about the rebase and an overview of what the reviewer should expect from the diff of diffs and range-diff -->