Improve comment in example code

This should make it more clear that even though `$` is used in 4 methods, only 2 of them are crucial for integrating the modal into the components lifecycle methods and the other 2 are just helpers.

Author: rileytomasek

examples/jquery-bootstrap/js/app.js

@@ -12,8 +12,8 @@ var BootstrapButton = React.createClass({
 });
 
 var BootstrapModal = React.createClass({
-  // The following four methods are the only places we need to
-  // integrate with Bootstrap or jQuery!
+  // The following two methods are the only places we need to
+  // integrate Bootstrap or jQuery with the components lifecycle methods.
   componentDidMount: function() {
     // When the component is added, turn it into a modal
     $(this.getDOMNode())