Use tile-view js and css files
Remove tile view mode code from script.js
Remove tile view mode styles from style.css
Add tile background layer
Change tile layer to for better layout
Restyle tile view
Rename script and style to code-hl

The master branch was originally used to implement highlighting in
fenced code blocks.
Restructure single tile for better layout

Also, the different hooks now are under different file names.

Merge branch 'tile-view'

* tile-view:
  Rename script and style to code-hl
  Restyle tile view
  Change tile layer to for better layout
  Add tile background layer
  Remove tile view mode styles from style.css
  Remove tile view mode code from script.js
  Use tile-view js and css files
Update README.md file