[css-grid-1] Note that span=1 item instructions are equivalent to, just a simplification of, the span=n instructions. #3616

Author: fantasai

css-grid-1/Overview.bs

@@ -4018,6 +4018,10 @@ Resolve Intrinsic Track Sizes</h3>
 			In all cases, if a track’s <a>growth limit</a> is now less than its <a>base size</a>,
 			increase the <a>growth limit</a> to match the <a>base size</a>.
 
+			Note: This step is a simplification of the steps below for handling spanning items,
+			and should yield the same behavior as running those instructions
+			on items with a span of 1.
+
 		<li id="algo-spanning-items">
 			<strong>Increase sizes to accommodate spanning items crossing content-sized tracks:</strong>
 			Next, consider the items with a span of 2