[css-grid] Fix linking error reported in https://lists.w3.org/Archives/Public/www-style/2015Dec/0288.html

Author: fantasai

css-grid/Overview.bs

@@ -3432,9 +3432,9 @@ Resolve Intrinsic Track Sizes</h3>
 					to the maximum of its items’ “min-size contributions”:
 					the value specified by its respective 'min-width' or 'min-height' properties
 					(whichever matches the relevant axis)
-					if the specified size is ''auto'',
+					if the specified size is ''width/auto'',
 					or else the item’s <a>min-content contribution</a>.
-					Note: For items with a specified minimum size of ''auto'' (the initial value),
+					Note: For items with a specified minimum size of ''min-width/auto'' (the initial value),
 					this is equivalent to a min-content minimum.
 				<li>
 					<strong>For min-content maximums:</strong>