[css-grid-1] Rephrase 'distribute extra space' opening to be more algorithmic for clarity. w3c#3648

Author: tabatkins

css-grid-1/Overview.bs

@@ -4330,16 +4330,18 @@ Resolve Intrinsic Track Sizes</h3>
 Distributing Extra Space Across Spanned Tracks</h4>
 
 	<div algorithm>
-		To <dfn noexport>distribute extra space</dfn>
-		to the [=base sizes=] or [=growth limits=] (the |affected size|s)
-		of a set of tracks (the |affected track|s)
-		to accommodate specific intrinsic size contributions (the |size contribution|s)
-		of a set of grid items spanning those tracks (the |item|s),
-		potentially preferring a subset of those tracks
-		(the optional |preferred track|s);
-		defaulting to all |affected tracks|
-		if there is no |track preference|--
-		as distinct from an empty list of |preferred track|s):
+		To <dfn noexport>distribute extra space</dfn>,
+		perform the following steps,
+		with these inputs:
+
+		* whether to affect [=base sizes=] or [=growth limits=] (the |affected size|s).
+		* which tracks to affect (the |affected track|s).
+		* what intrinsic size contributions are being accommodated (the |size contribution|s)
+			of which grid items spanning those tracks (the |item|s).
+		* optionally, a preferred subset of the |affected tracks| (the |preferred track|s),
+			indicating a |track preference| (even if the subset is empty);
+			if no |track preference|,
+			the |preferred track|s default to all |affected track|s.
 
 		<ol>
 			<li>