mention fubared state of overflow hidden on body in android and iOS to fix #8975 and #9315

getting-started.html

@@ -185,6 +185,9 @@ if (navigator.userAgent.match(/IEMobile\/10\.0/)) {
       <li>Tweak your percentages manually to get the perfect rounding for Safari (more difficult than the first option)</li>
     </ul>
     <p>We'll keep an eye on this though and update our code if we have an easy solution.</p>
+
+    <h3>Modals and mobile devices</h3>
+    <p>Support for <code>overflow: hidden</code> on the <code>&lt;body&gt;</code> element is quite limited in iOS and Android. To that end, when you scroll past the top or bottom of a modal in either of those devices' browsers, the <code>&lt;body&gt;</code> content will begin to scroll.</p>
   </div>