Make Forms => Textarea code snippet the same as example

docs/base-css.html

@@ -974,7 +974,7 @@ For example, <code>section</code> should be wrapped as inline.
             <textarea rows="3"></textarea>
           </form>
 <pre class="prettyprint linenums">
-&lt;textarea id="textarea" rows="3"&gt;&lt;/textarea&gt;
+&lt;textarea rows="3"&gt;&lt;/textarea&gt;
 </pre>
 
           <h3>Checkboxes and radios</h3>

docs/templates/pages/base-css.mustache

@@ -911,7 +911,7 @@
             <textarea rows="3"></textarea>
           </form>
 <pre class="prettyprint linenums">
-&lt;textarea id="textarea" rows="3"&gt;&lt;/textarea&gt;
+&lt;textarea rows="3"&gt;&lt;/textarea&gt;
 </pre>
 
           <h3>{{_i}}Checkboxes and radios{{/i}}</h3>