[css-grid] Fix link

Author: tabatkins

css-grid/Overview.bs

@@ -993,7 +993,7 @@ Reordered Grid Items: the 'order' property</h3>
 	when the visual order needs to be <em>out-of-sync</em>
 	with the speech and navigation order;
 	otherwise the underlying document source should be reordered instead.
-	See <a href="https://drafts.csswg.org/css-flexbox-1/#order-accessibility">Reordering and Accessibility</a>
+	See [[css-flexbox-1#order-accessibility]]
 	in [[CSS-FLEXBOX-1]].
 
 <h3 id='item-margins'>