accessible.js

/* By default, CodeMirror turns tabs into indents, which makes it difficult for keyboard-only
   users to "tab through" elements on a page.  Including this file and setting keyMap to 
   "accessible" removes the "tab" from CodeMirror's default KeyMap to remedy this problem */

(function() {
  var keyMap = CodeMirror.keyMap.accessible = {
    "Tab": false,
    "Shift-Tab": false, 
    fallthrough: "default"
  };
})();