feat: add baseBranch option

[prenaissance]

Closes #368

Change summary

This change adds a new action input baseBranch, which allows specifying the branch on which the PR will be opened on. This is useful for hotfixes. In my case, I trigger a release on merging to main, and this change would allow me to open a PR straight to main with the cherry-picked changes.

Specifications

A new input, baseBranch, can be specified to open the PR onto that branch. If not specified, the behavior will be as before, the PR would be opened on the branch the action runs on.

Example

Here's how running a hotfix workflow would look like:

The full workflow can be seen here https://github.com/prenaissance/changesets-test/blob/master/.github/workflows/changesets.yml

[changeset-bot]

⚠️ No Changeset found

Latest commit: 31ff97e

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[trueberryless]

LGTM 🎉 after I took a quick look

Very cool improvement imho.

Could you maybe add the explaination of this change into the README.md tho? So the documentation is up-to-date...

[prenaissance]

Accidentally pushed the wrong branch and the PR was closed automatically

[prenaissance]

Thanks for the feedback @trueberryless. I added the new action input in the README. Let me know if an example with a full workflow is needed.

[trueberryless]

Looks good to me 🎉

I'll leave the decision for an additional example with the baseBranch option to the actual maintainers, they know it the best...