Docs: Implementing an interface now instead of trying to extend it

git-svn-id: http://framework.zend.com/svn/framework/standard/trunk@20927 44c647ce-9c0f-0410-b52a-842ac1e357ba

documentation/manual/en/module_specs/Zend_Markup-Renderers.xml

@@ -71,7 +71,7 @@ echo $bbcode->render('my [foo]markup[/foo]');
             </para>
 
             <programlisting language="php"><![CDATA[
-class My_Markup_Renderer_Html_Upper extends Zend_Markup_Renderer_TokenConverterInterface
+class My_Markup_Renderer_Html_Upper implements Zend_Markup_Renderer_TokenConverterInterface
 {
 
     public function convert(Zend_Markup_Token $token, $text)