Demos: Updated page sections info on intro page

Fixes gh-7052

demos/intro/index.php

@@ -34,7 +34,7 @@
 
 		<h2>Pages & Dialogs</h2>
 
-		<p>A <a href="../pages/">page</a> in jQuery Mobile consists of an element with a <code> data-role="page"</code> attribute. Within the "page" container, any valid HTML markup can be used, but for typical pages in jQuery Mobile, the immediate children of a "page" are divs with data-roles of <code>"header"</code>, <code>"content"</code>, and <code>"footer"</code>. The baseline requirement for a page is only the page wrapper to support the navigation system, the rest is optional. </p>
+		<p>A <a href="../pages/">page</a> in jQuery Mobile consists of an element with a <code> data-role="page"</code> attribute. Within the "page" container, any valid HTML markup can be used, but for typical pages in jQuery Mobile, the immediate children of a "page" are divs with <code>data-role="header"</code>, <code>class="ui-content"</code>, and <code>data-role="footer"</code>. The baseline requirement for a page is only the page wrapper to support the navigation system, the rest is optional.</p>
 
 		<p>A page can be styled as a <a href="../pages-dialog/">dialog</a> that makes the page look like it's a modal style overlay. To give a standard page the appearance of a modal dialog, add the <strong>data-rel="dialog"</strong> attribute to the link. Transitions can also be set on dialog links.</p>