[css-values-3] Fix example in Property Value Examples

Author: lahmatiy

css-values-3/Overview.bs

@@ -350,8 +350,8 @@ Property Value Examples</h3>
 				<tr><td>'border-width'
 				    <td>[ &lt;length> | thick | medium | thin ]{1,4}
 				    <td>''2px medium 4px''
-				<tr><td>'text-shadow'
-				    <td>[ inset? && [ &lt;length>{2,4} && &lt;color>? ] ]# | none
+				<tr><td>'box-shadow'
+				    <td>[ inset? && &lt;length>{2,4} && &lt;color>? ]# | none
 				    <td>''3px 3px rgba(50%, 50%, 50%, 50%), lemonchiffon 0 0 4px inset''
 			</tbody>
 		</table>