Removes mentions of asm.js and other unneeded things, and focuses
on hopefully more useful content.
Also fixes the aspect ratio of some of the PNGs, which were converted
oddly from the SVG. This affected the landing page on github.
**all: folded to margins**
README: used local image, expanded license into a small section
CONTRIBUTING: added title
relooper README: removed licensing data (root of repo contains license)
Alon Zakai
Sam Clegg
Alon Zakai
Haneef Mubarak