Adding to changes section. Everything else seems editorial.

Author: rachelandrew

css-gcpm-3/Overview.bs

@@ -919,7 +919,8 @@ Changes since the <a href="http://www.w3.org/TR/2014/WD-css-gcpm-3-20140513/">13
 <ul>
 	<li>Clarify that bookmark is only created via 'bookmark-level' property. Remove <css>none</css> value from 'bookmark-label'.</li>
 	<li>Move the cross references, leaders, and bookmarks sections to the <a href="https://www.w3.org/TR/css-content-3/">CSS Generated Content Module</a>.</li>
-	<li>The spec has a new co-editor.</li>
+	<li>Incorrect break values were fixed. See <a href="https://github.com/w3c/csswg-drafts/issues/3524">Issue #3524</a>.</li>
+	<li>The spec has new editors.</li>
 </ul>