[mediaqueries-5] Mark non-normative sections as such

Author: frivoal

mediaqueries-5/Overview.bs

@@ -3370,6 +3370,10 @@ device-aspect-ratio</h3>
 <h2 id=priv-sec class=no-num>
 Appendix B: Privacy and Security Considerations</h2>
 
+	<em>This section is not normative.</em>
+
+<div class="non-normative">
+
 	Issue: this section is incomplete
 
 	The 'display-mode' media feature allows an origin
@@ -3381,9 +3385,15 @@ Appendix B: Privacy and Security Considerations</h2>
 	exploit the fact that an application is being displayed in fullscreen
 	to mimic the user interface of another application.
 
+</div>
+
 <h2 id="changes" class="no-num">
 Changes</h2>
 
+	<em>This section is not normative.</em>
+
+<div class="non-normative">
+
 <h3 id="changes-since-2020-07-31">
 Changes Since the 2020-07-31 Working Draft</h3>
 
@@ -3473,10 +3483,13 @@ The following additions were made to the First Public Working Draft of this modu
 		and 'forced-colors' media features.
 </ul>
 
+</div>
 
 <h2 class="no-num" id="acknowledgments">
 Acknowledgments</h2>
 
+	<em>This section is not normative.</em>
+
 This specification is the product of the W3C Working Group on
 Cascading Style Sheets.