Automatically trigger build when new data is published

[droher]

There are a few manual tasks I need to do in order to update Boxball when Retrosheet publishes new data. While they don't take very long, they're still a pain and ended up resulting in months of extra delay getting the latest data out. As an alternative:

• Set up a listener for changes in the latest commit hashes of baseballdatabank and retrosheet repos (and/or new releases)
• Automatically create a new branch/release draft, update the .env file with the new information, put up a PR, build images, and upload data files to OneDrive
• When PR is merged, push the images with their appropriate release labels