[css-cascade-4] Add myself to contributor list (w3c#6804)

Author: noamr

css-cascade-4/Overview.bs

@@ -1478,7 +1478,7 @@ Additions Since Level 2</h3>
 
 <h2 class="no-num" id="acknowledgments">Acknowledgments</h2>
 
-	David Baron, Tantek Çelik, Simon Sapin, and Boris Zbarsky contributed to this specification.
+	David Baron, Tantek Çelik, Simon Sapin, Noam Rosenthal, and Boris Zbarsky contributed to this specification.
 
 <h2 class=no-num id=priv-sec>
 Privacy and Security Considerations</h2>