Set up a workflow for releasing

[brettcannon]

https://docs.github.com/en/actions/creating-actions/releasing-and-maintaining-actions#setting-up-github-actions-workflows

[brettcannon]

https://github.com/JasonEtco/build-and-tag-action

[brettcannon]

The other way to solve this is to ditch the major-only tag and use a branch for it instead (e.g. v2 or release/v2 branch). The GitHub Actions docs suggest that any GitHub ref works, including a branch name, so people should be none the wiser that it's a branch instead of a tag. And since tags are just as mutable as a branch, having it be a tag is a bit pointless.

As such, if there's any workflow it would be to merge main into the appropriate major version branch and create a tag from that release branch.