Update index.html

Author: scottaohara

index.html

@@ -2802,7 +2802,7 @@ <h2>Definition of Roles</h2>
             </p>
             <p>
               Elements with the role <code>combobox</code> have an implicit <pref>aria-haspopup</pref> value of <code>listbox</code>. If the <code>combobox</code> popup element has a role other than
-              <rref>listbox</rref>, authors MUST specify an <pref>aria-haspopup</pref> value of <rref>tree</rref>, <rref>grid</rref>, <rref>menu</rref> or <rref>dialog</rref> that corresponds to the role of its popup.
+              <rref>listbox</rref>, authors MUST specify an <pref>aria-haspopup</pref> value of <rref>tree</rref>, <rref>grid</rref>, <rref>menu</rref>, or <rref>dialog</rref> that corresponds to the role of its popup.
             </p>
             <p>
               If the user interface includes an additional icon that allows the visibility of the popup to be controlled via pointer and touch events, authors SHOULD ensure that element has role