Make Forms => Default styles code snippet the same as example

docs/templates/pages/base-css.mustache

@@ -779,7 +779,8 @@
             <button type="submit" class="btn">{{_i}}Submit{{/i}}</button>
           </form>{{! /example }}
 <pre class="prettyprint linenums">
-&lt;form class="well"&gt;
+&lt;form&gt;
+  &lt;legend&gt;{{_i}}Legend{{/i}}&lt;/legend&gt;
   &lt;label&gt;{{_i}}Label name{{/i}}&lt;/label&gt;
   &lt;input type="text" placeholder="{{_i}}Type something…{{/i}}"&gt;
   &lt;span class="help-block"&gt;Example block-level help text here.&lt;/span&gt;