title: How can I include and update a service worker file into an existing app with only webVitals?
body: <p>I'm trying to make my existing Reactjs with typescript app a <strong>PWA</strong>, but the <strong>service-worker</strong> file was not included in the  version of Create-react-app, a <strong>reportWebVitals</strong> file was included instead. I would have suggested  I made a template of PWA with my Create-react-app and restart from scratch. but I've gone far with the development already. How do I go about this please?</p>