[css-values-3] Update Changes list.

Author: fantasai

css-values-3/Overview.bs

@@ -2198,6 +2198,15 @@ Changes</h2>
 
 	Changes since the <a href="https://www.w3.org/TR/2018/CR-css-values-3-20180814/">14 August 2018 Candidate Recommendation</a> are:
 
+	<ul>
+		<li>Added the new <a>bracketed range notation</a> to the CSS <a>value definition syntax</a>.
+			This has no normative implications on implementations,
+			just allows more routine annotation of ranges in future CSS specifications.
+			<a href="https://github.com/w3c/csswg-drafts/issues/355">Issue 355</a>)
+	</ul>
+
+	Changes since the <a href="https://www.w3.org/TR/2018/CR-css-values-3-20180814/">14 August 2018 Candidate Recommendation</a> are:
+
 	<ul>
 		<li>Defined <<'property'>> syntax to refer to the property without any top-level #-multiplier,
 			to make the notation usable with common list-valued property patterns.