Use 'fluid-container' instead of 'container-fluid' in the docs.

docs/scaffolding.html

@@ -242,7 +242,7 @@
       </div>
 <pre class="prettyprint linenums">
 &lt;body&gt;
-  &lt;div class="container-fluid"&gt;
+  &lt;div class="fluid-container"&gt;
     &lt;div class="sidebar"&gt;
       ...
     &lt;/div&gt;