0.9.0 Release

[andygrove]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

I plan on cutting the release candidate on October 14th. It would be nice to get as many of these features in as possible, but none should block the release.

• [ ] Improve User Guide
  • [ ] Fix references to DataFusion
  • [ ] https://github.com/apache/arrow-ballista/issues/272
  • [ ] Add scheduler UI screen shot and documentation
  • [ ] Explain how to use query graphs in tuning guide
• [ ] Update README
  • [ ] Update project status information
  • [ ] Add scheduler UI screenshot
• [ ] https://github.com/apache/arrow-ballista/pull/242
• [ ] Upgrade to DataFusion 13.0.0
• [ ] Prepare the release candidate
• [ ] Publish the release once the vote passes

Describe the solution you'd like :point_up:

Describe alternatives you've considered None

Additional context None