Handling the fullscreen functionality via the fullscreen JavaScript API.

Press »f« on the keyboard to enter fullscreen mode.

Typo fix

new paused mode feature (closes #144), controls and progress DOM elements are no longer required in HTML

  font-size: 18pt; instead of fount-size: 22pt;
  remove the "a" tag from def that forces font size, otherwise anchors in various contexts, e.g., headings, etc., will cause ugly rendering due to mismatched font size.
   specify font size for "pre" tags so that code listings more closely match browser rendering