Breaking: AMP is fast

This page demonstrates the AMP as PWA pattern:

1. It's a valid AMP page
2. It has a web app manifest: manifest.json
3. It installs a service worker:
   • Only installed for original domain, not AMP cache
   • When installed it caches some files for offline use
   • When running it intercepts requests, and serves from cache if possible
   • For URLs ending in amp.html (e.g amp.html), it injects JavaScript to augment the AMP page