ci: Enable automated versioning and NPM publishing

[kartojal]

From now on, commits must follow Conventional Commits, and release-please Github Action will maintain a CHANGELOG file and an automated PR to release versions with the latest changes. Once an automated PR bumps the version, it will also publish the package to the NPM registry.

You can read more about the release-please Github Action here: https://github.com/marketplace/actions/release-please-action