[css-counter-styles-3] Per WG resolution, change the example character for 'square' style to be U+25AA. Fixes w3c#6200.

Author: tabatkins

css-counter-styles-3/Overview.bs

@@ -1740,7 +1740,7 @@ Symbolic: ''disc'', ''circle'', ''square'', ''disclosure-open'', ''disclosure-cl
 		<dd>A hollow circle, similar to ◦ U+25E6 WHITE BULLET.
 
 		<dt><dfn id=square>square</dfn>
-		<dd>A filled square, similar to ◾ U+25FE BLACK MEDIUM SMALL SQUARE.
+		<dd>A filled square, similar to ▪ U+25AA BLACK SMALL SQUARE.
 
 		<dt><dfn id=disclosure-open>disclosure-open</dfn>
 		<dt><dfn id=disclosure-closed>disclosure-closed</dfn>
@@ -1771,8 +1771,8 @@ Symbolic: ''disc'', ''circle'', ''square'', ''disclosure-open'', ''disclosure-cl
 
 	@counter-style square {
 		system: cyclic;
-		symbols: \25FE;
-		/* ◾ */
+		symbols: \25AA;
+		/* ▪ */
 		suffix: " ";
 	}