[css-grid-1] Fix bikeshed formatting. w3c#4332

Author: Loirooriol

css-grid-1/Overview.bs

@@ -2868,7 +2868,7 @@ Line-based Placement: the 'grid-row-start', 'grid-column-start', 'grid-row-end',
 		<dt><dfn id='grid-placement-slot'><<custom-ident>></dfn>
 		<dd>
 			First attempt to match the <a>grid area</a>’s edge to a <a>named grid area</a>:
-			if there is a <a>named line</a> with the name ''<<custom-ident>>-start'' (for 'grid-*-start') / ''<<custom-ident>>-end'' (for 'grid-*-end'),
+			if there is a <a>named line</a> with the name <css><<custom-ident>>-start</css> (for 'grid-*-start') / <css><<custom-ident>>-end</css> (for 'grid-*-end'),
 			contributes the first such line to the <a>grid item</a>’s <a>placement</a>.
 
 			Note: <a>Named grid areas</a> automatically generate <a>implicit named lines</a> of this form,