PWA - Service worker for offline and perf

[spacerockzero]

• [x] HTTPS
• [x] H2
• [x] site is responsive across phone, tablet, and desktop sizes
• [x] 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
• [x] Loads while offline
• [x] metadata for "Add to Home screen", such as app manifest, etc. for each browser/OS
• [x] site works cross-browser
• [x] each page has a url? NA, so far
• [x] site content is indexed by search engines
• [ ] schema.org metadata provided
• [x] 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.