[css-borders-4] Reword corner-shape side shorthand (w3c#11793)

Author: noamr

css-borders-4/Overview.bs

@@ -458,11 +458,8 @@ Corner Shaping: the 'corner-shape' and 'corner-*-shape' properties</h4>
 	</pre>
 
 	<p>The 'corner-*-shape' shorthands set the two 'corner-*-*-shape'
-	longhand properties of the related side. If values are given before
-	and after the slash, then the values before the slash set the
-	horizontal radius and the values after the slash set the vertical radius.
-	If there is no slash, then the values set both radii equally.
-	The two values for the radii are given in the order
+	properties of the related side.
+	The two values for the shapes are given in the order
 	top-left, top-right for 'corner-top-shape',
 	top-right, bottom-right for 'corner-right-shape',
 	bottom-left, bottom-right for 'corner-bottom-shape',