revert i mapping change (#483)

Author: scottaohara

index.html

@@ -1269,7 +1269,7 @@ <h3>HTML Element Role Mappings</h3>
                 <a data-cite="HTML">`i`</a>
               </th>
               <td class="aria">
-                <a class="core-mapping" href="#role-map-emphasis">`emphasis`</a> role
+                <a class="core-mapping" href="#role-map-generic">`generic`</a> role
               </td>
               <td class="ia2"><div class="general">Use WAI-ARIA mapping</div></td>
               <td class="uia"><div class="general">Use WAI-ARIA mapping</div></td>