quote attribute value in selector in JS docs example

docs/_includes/js/overview.html

@@ -45,7 +45,7 @@ $('#myModal').modal({ keyboard: false })   // initialized with no keyboard
 $('#myModal').modal('show')                // initializes and invokes show immediately
 {% endhighlight %}
 
-  <p>Each plugin also exposes its raw constructor on a <code>Constructor</code> property: <code>$.fn.popover.Constructor</code>. If you'd like to get a particular plugin instance, retrieve it directly from an element: <code>$('[rel=popover]').data('popover')</code>.</p>
+  <p>Each plugin also exposes its raw constructor on a <code>Constructor</code> property: <code>$.fn.popover.Constructor</code>. If you'd like to get a particular plugin instance, retrieve it directly from an element: <code>$('[rel="popover"]').data('popover')</code>.</p>
 
   <h3 id="js-noconflict">No conflict</h3>
   <p>Sometimes it is necessary to use Bootstrap plugins with other UI frameworks. In these circumstances, namespace collisions can occasionally occur. If this happens, you may call <code>.noConflict</code> on the plugin you wish to revert the value of.</p>