Distribute to app store from CI

[emcniece]

https://github.com/sabjorn/BandcampEnhancementSuite/pull/38 introduces a CI pipeline example using Github Workflows. It should be possible to create a workflow that publishes this extension to the Chrome store using this: https://github.com/marketplace/actions/chrome-extension-upload-publish

Secrets will have to be managed by the extension owner, and can be added & obfuscated in the repo settings.

If this is an appealing idea, a workflow could be triggered when a release is published, or when master branch is updated.