MASTER: Added a <header> to the playground mark-up so I could extend the CodeMirror the entire height of the viewport. And added a media query to better handle the playback frame on viewports wider than 400px.
MASTER: Responsive fixes and made some alterations to how the “play frame” acts in the interface.
Fixes gh-69. Thanks to @abledaccess for the fix!
Merge remote-tracking branch 'abledaccess/master'

* abledaccess/master:
  MASTER: Responsive fixes and made some alterations to how the “play frame” acts in the interface.
  MASTER: Added a <header> to the playground mark-up so I could extend the CodeMirror the entire height of the viewport. And added a media query to better handle the playback frame on viewports wider than 400px.
gh-69: Updates credits section of the README.