Initial commit
Base SASS, HTML, JS for Pretty.

Added a loading screen.
Added sprites and a tiled space background.

Divide the window height/weidth by the background sprite size to tile
it over the whole backgorund.

Drew a little Slava astronaut floating aimlessly in space.
Added a Stein to the bottom of the screen.
Updating the README
Merge branch 'master' of https://github.com/jensechu/pretty