[css-nesting-1][editorial] Fixed most Bikeshed issues

Author: SebastianZ

css-nesting-1/Overview.bs

@@ -11,6 +11,7 @@ Editor: Tab Atkins-Bittner, Google, http://xanthir.com/contact/, w3cid 42199
 Former Editor: Adam Argyle, Google, https://nerdy.dev, w3cid 112669
 Abstract: This module introduces the ability to nest one style rule inside another, with the selector of the child rule relative to the selector of the parent rule.  This increases the modularity and maintainability of CSS stylesheets.
 Default Highlight: css
+Include MDN Panels: no
 </pre>
 
 <pre class=link-defaults>
@@ -1337,6 +1338,13 @@ Note: This means that multiple adjacent [=nested declarations rules=]
 (which is possible to create with e.g. {{CSSGroupingRule/insertRule}})
 will collapse into a single rule when serialized and parsed again.
 
+<h2 class=no-num id=privacy>Privacy Considerations</h2>
+
+No new privacy considerations have been reported on this specification.
+
+<h2 class=no-num id=security>Security Considerations</h2>
+
+No new security considerations have been reported on this specification.
 
 <!-- Big Text: changes -->