[css-scrollbars] Capitalization

Author: frivoal

css-scrollbars-1/Overview.bs

@@ -272,7 +272,7 @@ Value Definitions</h3>
 	(for example, when users choose a configuration option/setting that
 	always ensures a particular scrollbar color / use of system default scrollbars).
 
-	Note: when a user interacts with a scrollbar (e.g. hovering or activating),
+	Note: When a user interacts with a scrollbar (e.g. hovering or activating),
 	implementations may alter which scrollbar colors apply to which scrollbar parts.
 
 	<div class="example">