[css3-flexbox] Add line to Changes section about previous commit.

Author: tabatkins

css3-flexbox/Overview.html

@@ -4002,6 +4002,10 @@ <h2 class=no-num id=changes>Changes</h2>
     instead of raw document order when painting. (This was already stated in
     the ‘<a href="#order"><code class=property>order</code></a>’ section,
     but not in the section explicitly about painting order.)
+
+   <li> Specify that percentage margins/paddings on flex items are resolved
+    against their respective dimensions, not the inline dimension of the
+    containing block like blocks do.
   </ul>
 
   <p>A <a

css3-flexbox/Overview.src.html

@@ -3273,6 +3273,10 @@ <h2 class="no-num" id="changes">Changes</h2>
 		<li>
 			Clarified that 'order'-modified document order is used instead of raw document order when painting.
 			(This was already stated in the 'order' section, but not in the section explicitly about painting order.)
+
+		<li>
+			Specify that percentage margins/paddings on flex items are resolved against their respective dimensions,
+			not the inline dimension of the containing block like blocks do.
 	</ul>
 
 	<p>A <a href="http://dev.w3.org/csswg/css3-flexbox/issues-cr-2012">Disposition of Candidate Recommendation Comments</a> is available.