[css-ui-4] Turn compat issue into note, since we have resolved in favor

Author: frivoal

css-ui-4/Overview.bs

@@ -485,7 +485,7 @@ Omitted values are set to their initial values.
 		If the user attempts to create such a selection,
 		the UA must instead end the selection range at the element boundary.
 
-		Issue: As of the time of writing, experimental implementations do not all behave like this.
+		Note: As of the time of writing, experimental implementations do not all behave like this.
 		Firefox does.
 		Chrome and Safari almost do: for a selection started after the element
 		and trying to go backwards into the element