[css2] Minor example fix

--HG--
extra : convert_revision : svn%3A73dc7c4b-06e6-40f3-b4f7-9ed1dbc14bfc/trunk%401072

Author: ianbjacobs

css2/generate.src

@@ -264,7 +264,7 @@ P:before {content: "... "}
 <p>is applied to this source document:</p>
 
 <pre class="html-example">
-&lt;H3&lt;Centaurs&lt;/H3&gt;
+&lt;H3&gt;Centaurs&lt;/H3&gt;
 &lt;P&gt;have hoofs
 &lt;P&gt;have a tail
 </pre>