[css-color-adjust] Make computed value of color-scheme as specified.

Resolves w3c#3848

Author: lilles

css-color-adjust-1/Overview.bs

@@ -84,7 +84,7 @@ Opting Into a Preferred Color Scheme: the 'color-scheme' property {#color-scheme
 	Initial: auto
 	Applies to: all elements
 	Inherited: yes
-	Computed Value: the keyword ''auto'', or optional ''only'' keyword and ordered list of specified color scheme keywords, with any <<custom-ident>>s or repeated keywords dropped
+	Computed Value: as specified
 	</pre>
 
 	The 'color-scheme' property allows an element to indicate