[mediaqueries-5][editorial] Clarify changes between MQ4 and FPWD, fix w3c#10864

Author: svgeesus

mediaqueries-5/Overview.bs

@@ -3828,10 +3828,10 @@ The following additions were made to this module since the
 		Highlight some known issues inline in the document.
 </ul>
 
-<h3 id="changes-level-5">
-Changes since the Media Queries Level 4</h3>
+<h3 id="changes-for-fpwd">
+Changes for FPWD (since the Media Queries Level 4)</h3>
 
-The following additions were made to the First Public Working Draft of this module since the
+The following additions were made to create the First Public Working Draft of this module, since the
 <a href="https://www.w3.org/TR/mediaqueries-4/">Media Queries Level 4</a>:
 
 <ul>