[css-text-decor-4] Skip punctuation for emphasis marks, per w3c#839.

Author: xfq

css-text-decor-4/Overview.bs

@@ -427,7 +427,7 @@ Emphasis Mark Skip: the 'text-emphasis-skip' property</h3>
 		</tr>
 		<tr>
 			<th>Initial:</th>
-			<td>spaces
+			<td>spaces punctuation
 		</tr>
 		<tr>
 			<th>Applies to:</th>