keypress for left or right should not trigger when in input boxes

[shelane]

If you are in an input box, such as the search bar, and you click the left arrow, you are redirected to the previous page. This functionality comes from lines 226-239 of the learn.js file:

 jQuery(document).keydown(function(e) {
      // prev links - left arrow key
      if(e.which == '37') {
        jQuery('.nav.nav-prev').click();
        alert('handler for left arrow triggered in learn');
      }

      // next links - right arrow key
      if(e.which == '39') {
        jQuery('.nav.nav-next').click();
          alert('handler for right arrow triggered in learn');
      }
    });

This functionality should be disabled for input boxes because a user would expect a left or right arrow key to only move the typing cursor.

jQuery('input').keydown(function (e) {
         //  left and right arrow keys
         if (e.which == '37' || e.which == '39') {
             e.stopPropagation();
         }
     });

[matalo33]

Nice catch. Would you be able to submit this in a pull request?