[css-ui-4] Whoops, fix interest-delay shorthand to take one *or two* values. #9236

Author: tabatkins

css-ui-4/Overview.bs

@@ -2110,7 +2110,7 @@ User Interest Delay: the 'interest-delay-*' properties</h3>
 
 	<pre class="propdef shorthand">
 	Name: interest-delay
-	Value: <<'interest-delay-start'>>
+	Value: <<'interest-delay-start'>>{1,2}
 	</pre>
 
 	Some [=host language=] features
@@ -2164,8 +2164,9 @@ User Interest Delay: the 'interest-delay-*' properties</h3>
 	</dl>
 
 	The 'interest-delay' shorthand
-	sets both 'interest-delay-start' and 'interest-delay-end'
-	to the same specified value.
+	sets 'interest-delay-start' to its first value,
+	and 'interest-delay-end' to its second value
+	(or to the first value, if only one value is passed).
 
 	Note: In the future, the syntax of these properties might be expanded
 	to allow for customizing the delay