[css-grid-1][editorial] fix linking error

Author: tabatkins

css-grid-1/Overview.bs

@@ -1151,7 +1151,7 @@ Grid Items</h2>
 					<td>Fill grid area
 					<td>Fill grid area
 				<tr>
-					<th scope=row>''align-self/start''/''align-self/center''/etc.
+					<th scope=row>''align-self/start''/<l spec=css-align-3>''align-self/center''</l>/etc.
 					<td>''width/fit-content'' sizing (like floats)
 					<td>Use intrinsic size
 		</table>