[css-grid] Remove lingering mention of order/abspos.

Author: tabatkins

css-grid/Overview.bs

@@ -3072,9 +3072,9 @@ With a Grid Container as Containing Block</h3>
 	<div class='example'>
 		<pre>
 			.grid {
-				grid: 10rem 10rem 10rem 10rem / 1fr 1fr 1fr 1fr;
-				/* 4 columns of ''10rem'' each,
-				   4 equal-height rows filling the <a>grid container</a> */
+				grid: 1fr 1fr 1fr 1fr / 10rem 10rem 10rem 10rem;
+				/* 4 equal-height rows filling the <a>grid container</a>,
+				   4 columns of ''10rem'' each */
 				justify-content: center;
 				/* center the grid horizontally within the <a>grid container</a> */
 				position: relative;
@@ -3135,10 +3135,9 @@ With a Grid Container as Containing Block</h3>
 With a Grid Container as Parent</h3>
 
 	An absolutely-positioned child of a <a>grid container</a>
-	does not affect the placement of other items
+	is out-of-flow and not a <a>grid item</a>,
+	and so does not affect the placement of other items
 	or the sizing of the grid.
-	However, it does participate in the <a href="#auto-placement-algo">reordering step</a> (see 'order'),
-	which has an effect on painting order.
 
 	The <a href="https://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width">static position</a> [[!CSS21]]
 	of an absolutely-positioned child of a <a>grid container</a>