[TODO] Improve the PWA by updating the manifest.json, etc.

[gbowne1]

Create React App (which will be migrating from once we have a fully functional Twitch Bot) ships with:

• A default serviceWorker.js
• registerServiceWorker.js
• a default manifest.json
• Google Analytics package and file, reportWebVitals (uses the web-vitals package).

This is for a SWA/PWA. Even though this is not a PWA/SWA, We should consider updating this for:

1. good browser feature usage (the Application tab/panel in Firefox shows the manifest and serviceWorker(s) @ app running.
2. good SEO?
3. good results in Google Lighthouse/Google Pagespeed

Not sure what to use the serviceWorker for but it's there for usage.

My thought was also that we can use the service worker for caching assets, handling push notifications, and enabling offline functionality in the client. But this could be also done using the (ws) WebSocket or TCP connections to send and receive chat messages.