fix a few typos

fix app update note in sw.js

Added service worker notes in README.md

fix google fonts caching in service worker

fix sw.js

fix sw.js

fix service worker offline image

fix service worker offline image

fix service worker offline image

removed app bundle from source folder

added 'offline' and 'not found' pages to service worker

updated zuix library (v1.0.1)

improved cross-fading effect between cover and header title in details page

added parallax effect to details page cover as well

updated production index.js file