Think of this like a little boilerplate. This currently assumes you know how to user Firebase.
The first step is to create a Firebase project (https://firebase.google.com/). Be sure to enable Google Authentication. Next, we'll need some tooling.
npm install -g firebase-tools
Within app/, run firebase serve and open your browser to http://localhost:5000/.
When everything looks good, deploy it by running firebase deploy.
There aren't many external dependencies and the code is small so I've opted to avoid a build pipeline for now. If this is to be a true boilerplate, that will need to change.
Related to the build pipeline, this application assumes latest Chrome. A build tool could include BableJS so it can target lower browsers.