PWA - Service worker for offline and perf

[spacerockzero]

• HTTPS
• H2
• site is responsive across phone, tablet, and desktop sizes
• first load fast, even on 3G
• html5 routing, not page fragments? NA, so far. No page state in URL
• retain scroll position after BACK in history? NA, so far. No page state in URL
• Don't use server-side reload to navigate problems
• Loads while offline
• metadata for "Add to Home screen", such as app manifest, etc. for each browser/OS
• site works cross-browser
• each page has a url? NA, so far
• site content is indexed by search engines
• schema.org metadata provided
• social metadata provided
• inputs aren't obscured by on-screen keyboard
• content is easily shareable from standalone or fullscreen mode
• cache-first networking
• site informs user when they're offline
• be chill about push notifications, if you use them

[spacerockzero]

#44 and #45 took care of the high-ROI bits of this. closing.