[css-overflow-4] Fix bikeshed syntax

Author: fantasai

css-overflow-4/Overview.bs

@@ -265,32 +265,32 @@ Also, it must be the same for all elements in the page.
 
 The values of this property have the following meaning:
 
-<dl dfn-for="scrollbar-gutter">
-	<dt><dfn>''scrollbar-gutter/auto''</dfn>
+<dl dfn-for="scrollbar-gutter" dfn-type=value>
+	<dt><dfn>auto</dfn>
 	<dd><a>Classic scrollbars</a> consume space by creating a <a>scrollbar gutter</a>
-	when 'overflow' is ''overflow/scroll',
+	when 'overflow' is ''overflow/scroll'',
 	or when 'overflow' is ''overflow/auto'' and the box is overflowing.
 	<a>Overlay scrollbars</a> do not consume space.
 
-	<dt><dfn>''stable''</dfn>
+	<dt><dfn>stable</dfn>
 	<dd>The <a>scrollbar gutter</a> is present when
 	'overflow' is ''overflow/scroll'' or ''overflow/auto''
 	and the scrollbar is a <a>classic scrollbar</a>
 	even if the box is not overflowing,
 	but not when the scrollbar is an <a>overlay scrollbar</a>.
 
-	<dt><dfn>''always''</dfn>
+	<dt><dfn>always</dfn>
 	<dd>The <a>scrollbar gutter</a> is always present when
 	'overflow' is ''overflow/scroll'' or ''overflow/auto'',
 	regardless of the type of scrollbar or
 	of whether the box is overflowing.
 
-	<dt><dfn>''both''</dfn>
+	<dt><dfn>both</dfn>
 	<dd>If a <a>scrollbar gutter</a> would be present
 	on one of the inline start edge or the inline end edge of the box,
 	another <a>scrollbar gutter</a> must be present on the opposite edge as well.
 
-	<dt><dfn>''force''</dfn>
+	<dt><dfn>force</dfn>
 	<dd>When the ''scrollbar-gutter/force'' keyword is present
 	''scrollbar-gutter/stable'' and ''scrollbar-gutter/always'' take effect
 	when 'overflow' is ''overflow/visible'', ''overflow/hidden'' or ''overflow/clip''
@@ -326,7 +326,7 @@ and empty cells cases where the no space is reserved.
 		<th>Not overflowing
 	</thead>
 	<tr>
-		<th rowspan=3>'overflow/scroll'
+		<th rowspan=3>''overflow/scroll''
 		<th>''scrollbar-gutter/auto''
 		<td>G
 		<td>G
@@ -1067,7 +1067,7 @@ the ''continue/fragments'' value of the 'continue' property.
 
 <h3 id="fragment-styling">Fragment styling</h3>
 
-<h4 id="fragment-pseudo-element">The ::nth-fragment() pseudo-element</h4>
+<h4 id="fragment-pseudo-element">The ''::nth-fragment()'' pseudo-element</h4>
 
 	<p>
 		The <dfn selector>::nth-fragment()</dfn> pseudo-element