added a demo page with active, pressed, focused, disabled, and toggle states
changed last 'disabled' to 'toggle'
changed single quotes to double quotes, removed a commented line that was unnecessary
removed unnessary contribution note, there is a CONTRIBUTORS.txt file
moved unprefixed transform to end of css
Merge pull request #3 from WillsonSmith/pull-request-add-demo

added a demo page for paper-focusable