Remove all content and add archive notice.

[robdimsdale]

Summary

This PR removes all content from this repo and adds links to the replacement repositories in preparation for archving this repo.

Checklist

• [x] I have viewed, signed, and submitted the Contributor License Agreement.
• [ ] I have linked issue(s) that this PR should close using keywords or the Github UI (See docs)
• [ ] I have added an integration test, if necessary.
• [x] I have reviewed the styleguide for guidance on my code quality.
• [x] I'm happy with the commit history on this PR (I have rebased/squashed as needed).