Migrate async-nbgrader repo to illumidesk monorepo

[jgwerner]

Update the illumidesk/illumidesk monorepo with the illumidesk/async-nbgrader code.

• [ ] Update dev setup instructions
• [ ] Add Dockerfile to represent illumidesk/grader-notebook
• [ ] Migrate tests

[github-actions[bot]]

This issue has been tagged as stale due to inactivity