[css-scrollbars] Avoid RFC2119 language in notes

Author: frivoal

css-scrollbars-1/Overview.bs

@@ -290,7 +290,7 @@ Value Definitions</h3>
 	always ensures a particular scrollbar color / use of system default scrollbars).
 
 	Note: When a user interacts with a scrollbar (e.g. hovering or activating),
-	implementations may alter which scrollbar colors apply to which scrollbar parts.
+	implementations can alter which scrollbar colors apply to which scrollbar parts.
 
 	If the user agent displays the scrollbar without the [=track=],
 	they must ensure reasonable contrast between the [=thumb=] and what is behind it.
@@ -483,7 +483,7 @@ Interaction with non-standard features</h3>
 
 			Note: For situations where an element is to be scrolled <em>only</em> by programmatic means,
 			and not by direct user manipulation,
-			authors should use ''overflow: hidden'' instead of ''scrollbar-width: none''.
+			''overflow: hidden'' is appropriate, not ''scrollbar-width: none''.
 	</dl>
 
 	<div class=note>