a readme, short and sweet.

the most exciting thing is probably the link to the live version. other
stuff, later.

js/pixl/README.md

@@ -0,0 +1,9 @@
# pixl!
draw pixls.
see the [whirlwind intro][] for a quickstart.
it's live at <http://pixl.papill0n.org>.
[whirlwind intro]: https://github.com/heyLu/codegirls/blob/master/2013-12-17-christmas-special.md