fixed #4598, typo, manually

docs/javascript.html

@@ -376,7 +376,7 @@ $('#myModal').on('hidden', function () {
 
 
 
-        <!-- Dropdown
+        <!-- Dropdowns
         ================================================== -->
         <section id="dropdowns">
           <div class="page-header">
@@ -479,7 +479,7 @@ $('#myModal').on('hidden', function () {
           <p>Add <code>data-toggle="dropdown"</code> to a link or button to toggle a dropdown.</p>
 <pre class="prettyprint linenums">
 &lt;div class="dropdown"&gt;
-  &lt;a class="dropdown-toggle" href="#"&gt;Dropdown trigger&lt;/a&gt;
+  &lt;a class="dropdown-toggle" data-toggle="dropdown" href="#"&gt;Dropdown trigger&lt;/a&gt;
   &lt;ul class="dropdown-menu" role="menu" aria-labelledby="dLabel"&gt;
     ...
   &lt;/ul&gt;