build: automate release flow

[sherwinski]

Adds a GitHub Action to perform the following:

• Kick off whenever a new commit is made on the default (main) branch
• Bump package version in package.json
  • Version bump follows semantic versioning
  • Avoid automatically publishing new major versions to prevent unintended releases
• Publish updated package to registry (npmjs.com)
• Add a new git tag
• Generate release notes and add them to the changelog
• Publish a new release to GitHub, includes change notes in release body

Note: the script is set to run in dry-run mode for debugging purposes. After initial test runs, this flag should be removed.