ADAPT-2518: Added autorelease github action.

[nplowman]

READY FOR REVIEW

Summary

Adds autorelease Github action. This action:

• Automatically updates the changelog
• Increments the release version (both in package.json and with a git tag) based on Github label. (i.e. patch, minor, major, alpha, beta, rc)
• Runs 'npm run package' and commits any new changes to dist folder.
• Publishes latest package to npm.

Needed By (Date)

• Next 2-3 days

Urgency

• 3/10. (Process improvement, but nothing urgent or time sensitive).

Steps to Test

This one will be a bit tricky to test, as the action is only fired when merging to "main".
You may need to create a few dummy PRs that make changes to the README file or something along those lines to test the different scenarios.

• Create a new pull request, with base branch of "main".
• Add one of the following labels: "patch", "minor", "major", "alpha", "dev", or "rc"
• Merge the PR.
• Click the "Actions" tab in Github, validate that the action fired correctly and there are no log errors.
• View the "Code" tab in Github. You should see that the CHANGELOG file has been updated with commit messages from the release, package.json updated with a new version number, and a new tag should also be visible.
• Check releases in Github (under code -> tags -> releases) and ensure release notes are present.
• Github release should also show 'latest release', except for alpha, beta, and rc releases, which should show a "Prerelease" tag.

Associated Issues and/or People

• https://stanfordits.atlassian.net/browse/ADAPT-2518
• This is essentially a clone of: https://stanfordits.atlassian.net/browse/ADAPT-2517
• https://www.npmjs.com/package/auto-changelog

See Also

• PR Checklist

[nplowman]

@sherakama
Make sure to add the NPM_TOKEN to the secrets for this repo before merging.

Also, I ran into a build error that was being caused by 'autoprefixer' being missing. Not sure how that issue got introduced, but just went ahead and fixed it within this PR.

[sherakama]

GTG