[css-grid] Whoops, nope, order-modified *document* order. Order-modified grid order doesn't even exist until *after* auto-placement.

Author: tabatkins

css-grid/Overview.bs

@@ -2910,7 +2910,7 @@ Grid Item Placement Algorithm</h3>
 	If it is instead set to ''grid-auto-flow/column'',
 	swap all mentions of rows and columns, inline and block, etc. in this algorithm.
 
-	Note: The <a>auto-placement algorithm</a> works with the <a>grid items</a> in <a>order-modified grid order</a>,
+	Note: The <a>auto-placement algorithm</a> works with the <a>grid items</a> in <a>order-modified document order</a>,
 	not their original document order.
 
 	0. <strong>Generate anonymous grid items</strong>