[css-syntax] Link to Milestone for the DoC.

Author: tabatkins

css-syntax-3/Overview.bs

@@ -3470,6 +3470,8 @@ Changes from the 20 February 2014 Candidate Recommendation</h3>
 
 	* Clarified on every range that they are inclusive.
 
+	<a href="https://github.com/w3c/csswg-drafts/milestone/5?closed=1">A Disposition of Comments is available.</a>
+
 
 <h3 id="changes-WD-20131105">
 Changes from the 5 November 2013 Last Call Working Draft</h3>