[css-grid-3][editorial] dashed -> cross-hatched

Author: tabatkins

css-grid-3/Overview.bs

@@ -1187,7 +1187,7 @@ Stacking-axis Self Alignment: the 'align-self'/'justify-self' and 'align-items'/
 		<figcaption>
 			The three highlighted items are the only ones with "gaps" following them,
 			so they're the only ones that will respond to 'align-items'.
-			Their [=alignment containers=] are indicated by the dashed areas.
+			Their [=alignment containers=] are indicated by the cross-hatched areas.
 		</figcaption>
 	</figure>