[css-contain-2] Elements stay relevant to the user during a view transition (#8847)

* Elements stay relevant to the user during a view transition

Closes #8060

* Rephrase using 'involved in a view transitino'

* Remove redundant line

Author: noamr

css-contain-2/Overview.bs

@@ -1681,6 +1681,9 @@ Suppressing An Element's Contents Entirely: the 'content-visibility' property {#
 			content-visibility/content-visibility-with-top-layer-005.html
 			content-visibility/content-visibility-with-top-layer-006.html
 			</wpt>
+
+		* The element has a [=flat tree=] descendant that is [=involved in a view transition=].
+
 	</div>
 
 

css-view-transitions-1/Overview.bs

@@ -502,7 +502,7 @@ urlPrefix: https://wicg.github.io/navigation-api/; type: interface;
 
 ## Named and transitioning elements ## {#named-and-transitioning}
 
-	[=/Elements=] have an <dfn>involved in a view transition</dfn> boolean, initially false.
+	[=/Elements=] have an <dfn export>involved in a view transition</dfn> boolean, initially false.
 
 	[=/Elements=] that either have a 'view-transition-name' [=computed value=] that is not ''view-transition-name/none'',
 	or are [=involved in a view transition=], form: