fix: improve registerComplete page header

Author: themightychris

html-templates/register/registerComplete.tpl

@@ -5,9 +5,9 @@
 {block "content"}
     {$User = $data}
 
-    <div class="page-header">
-        <h1>{_ "Registration complete"}</h1>
-    </div>
+    <header class="page-header">
+        <h2>{_ "Registration complete"}</h2>
+    </header>
 
     {capture assign=personLink}<a href="{$User->getUrl()|escape}">{$User->Username|escape}</a>{/capture}
     <p class="lead">{"Your username for %s is: %s"|_|sprintf:Laddr::$siteName:$personLink}</p>