Fixed typo: missing s in "asynchronous"

index.html

@@ -3646,7 +3646,7 @@ <h2 id="faq">F.A.Q.</h2>
         <a href="#Events">Synchronous events</a> are used as the fundamental
         building block, not a difficult-to-reason-about run loop, or by constantly
         polling and traversing your data structures to hunt for changes. And if
-        you want a specific event to be aynchronous and aggregated,
+        you want a specific event to be asynchronous and aggregated,
         <a href="http://underscorejs.org/#debounce">no problem</a>.
       </li>
       <li>