[css-counter-styles-3][editorial] add change to appendix

Author: tabatkins

css-counter-styles-3/Overview.bs

@@ -2654,6 +2654,9 @@ Changes since the July 2021 Candidate Recommendation</h3>
 		<a href="https://github.com/w3c/csswg-drafts/commit/20a3d9ca02f235d8af13aa2bb05f725448371ad2">this commit</a>.
 		(<a href="https://github.com/w3c/csswg-drafts/issues/8870">Issue 8870</a>)
 
+	* Fixed the accidental desync between disallowed name keywords in the syntax vs the OM.
+	(<a href="https://github.com/w3c/csswg-drafts/issues/8186">Issue 8186</a>)
+
 <h3 id='changes-2017'>
 Changes since the December 2017 Candidate Recommendation</h3>