Fix typo

Author: Jona Koudijs

_includes/docs.html

@@ -19,7 +19,7 @@ <h4>Authentication</h4>
       <p>
         No authentication or verification is required to use the API. App information
         is retrieved when changes are reported by Steam and are stored in a database.
-        Generally updates areis available within seconds after they are updated.
+        Generally updates are available within seconds after they are updated.
       </p>
     </div>
   </div>