[css-grid][css-flexbox] Move mention of order-modified order to preceding notes, harmonize how they talk about anonymous item generation.

Author: tabatkins

css-flexbox/Overview.bs

@@ -2232,25 +2232,16 @@ Flex Layout Algorithm</h2>
 
 	The following sections define the algorithm for laying out a flex container and its contents.
 
+	Note: Flex layout works with the <a>flex items</a> in <a>order-modified document order</a>,
+	not their original document order.
+
 <h3 id='box-manip'>
 Initial Setup</h3>
 
-	<ol start=0>
+	<ol start=1>
 		<li id='algo-anon-box'>
 			<strong>Generate anonymous flex items</strong>
-			as described in the <a href="#flex-items">Flex Items</a> section.
-
-		<li id='algo-flex-order'>
-			<strong>Re-order the flex items (and any absolutely positioned flex container children) according to their 'order'.</strong>
-			The flex items with the lowest (most negative) 'order' values are first in the ordering.
-			If multiple flex items share an 'order' value,
-			they're ordered by document order.
-			This effectively changes the order of their boxes in the box-tree,
-			and how the rest of this algorithm deals with the generated flex items.
-
-			Note: Absolutely-positioned children of a flex container
-			do not participate in flex layout,
-			but are reordered together with any <a>flex item</a> children.
+			as described in [[#flex-items]].
 	</ol>
 
 <h3 id='line-sizing'>

css-grid/Overview.bs

@@ -2910,18 +2910,13 @@ 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.
 
-	0. <strong>Re-order the grid items
-		(and any absolutely-positioned grid container children)
-		according to their 'order'.</strong>
-		The grid items with the lowest (most negative) 'order' values are first in the ordering.
-		If multiple grid items share an 'order' value,
-		they're ordered by document order.
-		This effectively changes the order of their boxes in the box-tree,
-		and how the rest of this algorithm deals with the generated grid items.
-
-		Note: Absolutely-positioned children of a grid container
-		do not participate in grid layout,
-		but are reordered together with any <a>grid item</a> children.
+	Note: The <a>auto-placement algorithm</a> works with the <a>grid items</a> in <a>order-modified grid order</a>,
+	not their original document order.
+
+	0. <strong>Generate anonymous grid items</strong>
+		as described in [[#grid-items]].
+		(Anonymous <a>grid items</a> are always auto-placed,
+		since their boxes can't have any <a>grid-placement properties</a> specified.)
 
 	1. <strong>Position anything that's not auto-positioned.</strong>