remove some outdated, incorrect $.getScript examples

notebook/static/custom/custom.js

@@ -63,16 +63,6 @@
  *        });
  *    });
  *
- * __Example 3:__
- *
- *  Use `jQuery.getScript(url [, success(script, textStatus, jqXHR)] );`
- *  to load custom script into the notebook.
- *
- *    // to load the metadata ui extension example.
- *    $.getScript('/static/notebook/js/celltoolbarpresets/example.js');
- *    // or
- *    // to load the metadata ui extension to control slideshow mode / reveal js for nbconvert
- *    $.getScript('/static/notebook/js/celltoolbarpresets/slideshow.js');
  *
  *
  * @module IPython

notebook/static/notebook/js/celltoolbarpresets/example.js

@@ -1,13 +1,6 @@
 // Copyright (c) Jupyter Development Team.
 // Distributed under the terms of the Modified BSD License.
 
-// Example Use for the CellToolbar library
-// add the following to your custom.js to load
-// Celltoolbar UI for slideshow
-
-// ```
-// $.getScript('/static/js/celltoolbarpresets/example.js');
-// ```
 define([
     'notebook/js/celltoolbar',
 ], function(celltoolbar) {