Add a PR template and a squash template so that the review process on forgejo is easier.

Type: skip

Make your own fork of this on forgejo. Push this commit to the default branch. Create a PR and verify you can see the template being applied.
Once you created the PR, click "create squash commit" button. Verify that you can see the commit message title is the same as the PR title and the body is the PR body followed by "Reviewed-on".