Language tweak

Author: jakearchibald

css-view-transitions-1/Overview.bs

@@ -203,7 +203,7 @@ urlPrefix: https://html.spec.whatwg.org/multipage/rendering.html; type: dfn;
 	a [=/list=] of [=pseudo-elements=].
 	Initially an empty [=/list=].
 
-	A [=pseudo-element parent=]'s [=pseudo-element parent/children=] should be laid out in the order they appear in the [=/list=], according to their styles.
+	A [=pseudo-element parent=]'s [=pseudo-element parent/children=] are laid out in the order they appear in the [=/list=], according to their styles.
 
 	When a [=pseudo-element=] |pseudo| is part of a [=pseudo-element parent=] |parent|'s [=pseudo-element parent/children=],
 	and |parent| is a [=pseudo-element=],