[css-grid-1] Used value of track listing is only when grid container …

…box is generated. #4063

css-grid-1/Overview.bs

@@ -1899,7 +1899,7 @@ Resolved Value of a Track Listing</h4>
 	The 'grid-template-rows' and 'grid-template-columns' properties are
 	<a>resolved value special case properties</a>. [[!CSSOM]]
 
-	When an element's 'display' is ''grid'' or ''inline-grid'' and it generates a box,
+	When an element generates a [=grid container box=],
 	the <a href="https://www.w3.org/TR/cssom/#resolved-values">resolved value</a>
 	of the 'grid-template-rows' and 'grid-template-columns' properties is the <a>used value</a>,
 	serialized with: