[mediaqueries] Update change section

Author: frivoal

mediaqueries/Overview.bs

@@ -2148,6 +2148,7 @@ The following changes were made to this specification since the
 <a href="https://www.w3.org/TR/2017/WD-mediaqueries-4-20170519/">19 May 2017 Working Draft </a>:
 <ul>
 	<li>Changed range media features to be <a>false in the negative range</a> instead of failing to parse negative values.
+	<li>Included enough informaton about the color spaces needed by 'color-gamut' directly into the specification.
 </ul>
 
 <h3 id="changes-2012">