Setup release automation

[NullVoxPopuli]

This automation uses: release-plan via this npx boilerplate generator, which is a hybrid of the best parts of release-it and changesets, where:

• changelog entries are managed via labels (this list is a bit hard coded, but is sufficient)
• if a maintainer can merge, they can release
• no maintainer needs to have access to npm, nor push-access to main, they only need to be able to merge PRs

The one-time setup:

• an NPM_TOKEN
• permission for actions to create pull requests
• we'll want to enable "releases" in the settings for this repo
  • an initial git tag pushed (we can checkout the existingly published -- I've determined this to be 0.1.0 for signal-polyfill which was 2024-03-31T19:18:08.630Z, or matching commit: d811fce (hopefully -- hard to tell for sure, tbh, but the commit used for publish cannot be newer than the publish timestamp)

Example:

• https://github.com/NullVoxPopuli/signal-utils/tree/main
• Feature PR: New Util: ReactiveArray proposal-signals/signal-utils#9
  • labeled with enhancement
• that PR then merged
• The release preview workflow opened this PR
  • Prepare Release proposal-signals/signal-utils#8
• that PR is then merged
  • git tag created
  • github release created
  • npm release occurred

[NullVoxPopuli]

this is all boilerplate maintained by https://github.com/embroider-build/create-release-plan-setup

[NullVoxPopuli]

this is all boilerplate maintained by https://github.com/embroider-build/create-release-plan-setup

[NullVoxPopuli]

a unified changelog for all packages in the repo

[littledan]

Thanks for creating this automation. I am not sure of the best strategy for maintaining this (unstable) polyfill, so I am not ready to land this patch yet.

[littledan]

We'll be developing this code in a different repo.