Github Action for creating PR notes

[chendaniely]

When the PR github action fails with this message

Pushing pull request branch to 'origin/main'
  /usr/bin/git push --force-with-lease origin main:refs/heads/main
  remote: Permission to ttimbers/rvmypr-ttimbers.git denied to github-actions[bot].
  fatal: unable to access 'https://github.com/ttimbers/rvmypr-ttimbers/': The requested URL returned error: 403
  Error: The process '/usr/bin/git' failed with exit code 128

make sure the repo settings allow github actions to work with PRs

students will need to manually check off the box if they use a template repo

[chendaniely]

This information has been added to the repo usage instructions (the one we have students template): https://github.com/ttimbers/review-my-pull-request#usage