[css-grid-3] Remove masonry-auto-flow

Remove masonry-auto-flow based on the resolution here:
#10231

Author: stwrt

css-grid-3/Overview.bs

@@ -276,66 +276,6 @@ Masonry Layout Algorithm</h3>
 			to <code><var>max_pos</var> + <var>margin-box-end</var> + <var>grid-gap</var></code>.
 	</ol>
 
-<h3 id="masonry-auto-flow">
-The ''masonry-auto-flow'' Property</h3>
-
-	The [[#masonry-layout-algorithm]] above can be modified in two ways, using the new 'masonry-auto-flow' property:
-
-	<pre class='propdef'>
-		Name: masonry-auto-flow
-		Value: [ pack | next ] || [definite-first | ordered ]
-		Initial: pack
-		Applies to: [=grid containers=] with [=masonry layout=]
-		Inherited: no
-		Percentages: n/a
-		Computed value: specified keyword(s)
-		Animation type: discrete
-	</pre>
-
-
-	First, picking definite items first for placement can be inhibited
-	by specifying the ''masonry-auto-flow/ordered'' keyword
-	so that a plain [=order-modified document order=] is used instead.
-	Second, instead of placing the items in the track(s) with the most remaining space as described above
-	we can place them one after another in the [=grid axis=]
-	by specifying the ''masonry-auto-flow/next'' keyword,
-	for <a href="examples/masonry-auto-flow-next.html">example</a>:
-
-	<div class="example">
-		```css
-			<style>
-			.grid {
-			  display: inline-grid;
-			  grid: masonry / repeat(3, 2ch);
-			  border: 1px solid;
-			  masonry-auto-flow: next;
-			}
-
-			item { background: silver }
-			item:nth-child(2n+1) {
-			  background: pink;
-			  height: 4em;
-			}
-			</style>
-		```
-		```html
-			<div class="grid">
-			  <item>1</item>
-			  <item>2</item>
-			  <item>3</item>
-			  <item>4</item>
-			</div>
-		```
-
-		<figure>
-			<img src="images/grid-auto-flow-example-1.png">
-			<figcaption>Rendering of the ''masonry-auto-flow: next'' example above.</figcaption>
-		</figure>
-
-		(Without ''masonry-auto-flow: next'', item 4 would be placed below item 2.)
-
-	</div>
-
 <h2 id="containing-block">
 Containing Block</h2>