[mediaqueries] Fix typo in example

Author: frivoal

mediaqueries/Overview.src.html

@@ -925,7 +925,7 @@ <h3 id="grid">grid</h3>
 
 <pre>
 @media handheld and (grid) and (max-width: 15em) { &hellip; }</code>
-<code>@media handheld and (grid) and (device-max-height: 7em) { &hellip; }
+<code>@media handheld and (grid) and (max-device-height: 7em) { &hellip; }
 </pre>
 
 </div>