Reformat the README file.
Reformat the README file.

Reformat the README file as proper ReST markup, so that my head does
not hurt every time I read it. With a few spelling and style fixes.

R=gary.poster
CC=
https://codereview.appspot.com/6814049

mitechie/juju-gui,CanonicalJS/juju-gui,mitechie/juju-gui,CanonicalJS/juju-gui,mitechie/juju-gui,bac/juju-gui,jrwren/juju-gui,bac/juju-gui,bac/juju-gui,bac/juju-gui,jrwren/juju-gui,jrwren/juju-gui,jrwren/juju-gui,CanonicalJS/juju-gui,mitechie/juju-gui