Adding myself as co-editor of css-gcpm

Author: rachelandrew

css-gcpm-3/Overview.bs

@@ -8,6 +8,7 @@ Group: csswg
 ED: https://drafts.csswg.org/css-gcpm/
 TR: https://www.w3.org/TR/css-gcpm-3/
 Editor: Mike Bremford, BFO, mike@bfo.com, w3cid 118053
+Editor: Rachel Andrew, Google, rachelandrew@google.com, w3cid 81117
 Former Editor: Dave Cramer, Hachette Livre, dave.cramer@hbgusa.com, w3cid 65283
 Former Editor: Håkon Wium Lie, Opera Software
 Link defaults: css-content-3 (property) counter-increment, css-content-3 (property) counter-reset, css21 (property) string, css2 (property) max-height
@@ -918,6 +919,7 @@ 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>
 </ul>