Release Automation Meta Issue

[DanielRosenwasser]

We're trying to find ways to reduce the amount of manual work that a release requires. This currently includes

• Automate release branch creation #36863
• Automate DefinitelyTyped and ATA infrastructure during nightly publishes #36864
• ATA doesn't work on Nightlies during the RC period #34818

More may be added to this list over time

[orta]

It doesn't look like we deploy the main npm packages through automation, but I think I can make it so publishing a new release could trigger a build for the playground (via the same mechanism we do PR deploys)