[css-animations-2] Add separate privacy and security sections

Author: svgeesus

css-animations-2/Overview.bs

@@ -802,9 +802,12 @@ console.log(anim.playState); // Should be 'running'.
 
 </div>
 
-
-
-<h2 id="priv-sec">
-Privacy and Security Considerations</h2>
-
-This specification introduces no new privacy or security considerations.
+<h2 id="priv">
+  Privacy Considerations</h2>
+  
+  No privacy concerns have been reported on this specification.
+  
+  <h2 id="sec">
+  Security Considerations</h2>
+    
+  No security concerns have been reported on this specification.