[css-overflow-3] Update changelog

Author: frivoal

css-overflow-3/Overview.bs

@@ -1674,6 +1674,11 @@ Fragmentation of Overflow: the 'continue' property</h3>
 
 	This appendix is <em>informative</em>.
 
+<h3 id="changes-since-2021-12-02">
+Changes from the <a href="https://www.w3.org/TR/2021/WD-css-overflow-3-20211202/">2021-12-02 Working Draft</a></h3>
+
+	No significant change yet.
+
 <h3 id="changes-since-2020-06-03">
 Changes from the <a href="https://www.w3.org/TR/2020/WD-css-overflow-3-20200603/">2020-06-03 Working Draft</a></h3>