[css-values] Clarify that re-orderable combinators allow interleaving.

Author: fantasai

css-values/Overview.bs

@@ -140,6 +140,14 @@ Component value combinators</h3>
 	[ a b ] | [ c || [ d && [ e f ]]]
 	</pre>
 
+	For re-orderable combinators (||, &&),
+	ordering of the grammar does not matter:
+	components in the same grouping may be interleaved in any order.
+	Thus, the following lines are equivalent:
+	<pre>
+<!---->a || b || c
+<!---->b || a || c</pre>
+
 <h3 id="component-multipliers">
 Component value multipliers</h3>
 
@@ -1662,6 +1670,7 @@ Changes</h2>
     <li>Added notation for restricting the length of comma-separated lists
         specified with the ''#'' notation.
     <li>Clarified handling of ''toggle()'' when used in shorthand declarations.
+    <li>Clarified that stringing together re-orderable combinations allows interleaving.
     <li>Changed syntax references from the 2.1 grammar to the Syntax spec.
   </ul>