This creates a new repository root (empty), clones all commits and rebases them to the new root (review).
The diff between review and empty therefor includes the whole codebase as addition.
git switch --orphan empty
git commit --allow-empty -m 'empty'
git checkout main
git checkout -b review
git rebase empty
git push origin empty review
git checkout mainNavigate to the repos PRs and create a new one for empty <- review.
If you want to add new commits from main to the review
git checkout main
git checkout -b tmp
git rebase review
git checkout review
git reset tmp --hard
git branch -D tmp
git push origin review
git checkout main