[css-lists] Typo fix

Author: SimonSapin

css-lists/Overview.html

@@ -1272,7 +1272,7 @@ <h2 class="heading settled heading" data-level=10 id=ua-stylesheet><span class=s
   ol[reversed] {
     counter-reset: list-item attr(start integer, **magic**);
     /* Where **magic** is the number of child &lt;li&gt; elements. */
-    counter-increment: list-item 1;
+    counter-increment: list-item -1;
   }
   ol[reversed] &gt; li {
     counter-increment: list-item -1;

css-lists/Overview.src.html

@@ -1310,7 +1310,7 @@ <h2 id='ua-stylesheet'>
 		ol[reversed] {
 			counter-reset: list-item attr(start integer, **magic**);
 			/* Where **magic** is the number of child &lt;li> elements. */
-			counter-increment: list-item 1;
+			counter-increment: list-item -1;
 		}
 		ol[reversed] > li {
 			counter-increment: list-item -1;