Update index.html

Author: LanWei22

index.html

@@ -7372,6 +7372,9 @@ <h3>Processing actions</h3>
      <dd>Create a new <a>pointer input source</a>. Let the
       new <a>input source</a>’s <a>pointer type</a> be set to the value
       of <var>parameters</var>’s <code>pointerType</code> property.
+    
+     <dt>"<code>wheel</code>"
+     <dd>Create a new <a>wheel input source</a>.
     </dl>
 
    <li><p>Add <var>source</var> to the <a>current session</a>’s list
@@ -7422,6 +7425,11 @@ <h3>Processing actions</h3>
     a pointer action</a> with parameters <var>id</var>,
     <var>parameters</var>, and <var>action item</var>.
 
+   <li><p>Otherwise, if <var>type</var> is "<code>wheel</code>"
+    let <var>action</var> be the result of <a>trying</a> to <a>process
+    a wheel action</a> with parameters <var>id</var>, and
+    <var>action item</var>.
+
    <li><p>Append <var>action</var> to <var>actions</var>.
   </ol>