no issue
- Renovate will open PRs to bump dependencies but these are unassigned
- Renovate does have the ability to set assignees, but these are blanket
assigns not based upon the package that is being upgraded
- we want to assign them to the owners of the package that is being
upgraded
- I've created the `gh-auto-assign` GitHub CLI exntension which reads a
`.github/AUTO_ASSIGN` file and assign PRs based upon the entries listed
- this commit adds the initial `AUTO_ASSIGN` file and GitHub Actions
workflow to trigger when a PR is opened
