all highlight pseudo styles, not just the root

Co-authored-by: fantasai <fantasai.bugs@inkedblade.net>

Author: delan

css-pseudo-4/Overview.bs

@@ -994,8 +994,8 @@ Text and Text Decorations</h4>
   and are not propagated to descendants
   except via property [=inheritance=] (as described [[#highlight-cascade|above]]).
 
-  Note: Unlike the element’s own decorations,
-  decorations declared on the root element’s highlights
+  Note: Unlike the originating element’s own decorations,
+  decorations declared on a highlight pseudo-element
   propagate to [=out-of-flow|out-of-flow elements=] and [=inline blocks=],
   with thickness and position varying between descendants.