[css-align-3][editorial] Use parallel structure for cross-reference to multicol

Author: fantasai

css-align-3/Overview.bs

@@ -2081,9 +2081,10 @@ Row and Column Gutters: the 'row-gap' and 'column-gap' properties</h3>
 	<dl>
 		<dt id="gap-multicol"><a>multi-column containers</a>
 		<dd>
-			'column-gap' specifies the [=gutter=] between adjacent <a>column boxes</a>.
-			See [[CSS-MULTICOL-1]] for details on how this affects the layout of multicol elements.
-			'row-gap' is introduced in [[CSS-MULTICOL-2]].
+			'column-gap' specifies the [=gutter=] between adjacent <a>column boxes</a>,
+			see [[CSS-MULTICOL-1]].
+			'row-gap' specifies the [=gutter=] between the rows of [=column boxes=] established by 'column-height',
+			see [[CSS-MULTICOL-2]].
 
 		<dt id="gap-flex"><a>flex containers</a>
 		<dd>