[css-align-3] Additional wording tweaks to overflow + content alignment

Author: tabatkins

css-align-3/Overview.bs

@@ -1088,8 +1088,9 @@ Overflow and Scroll Positions</h3>
 	for consistency,
 	any non-''align-content/normal'' value of 'align-content' or 'justify-content'
 	causes the <a>scrollable overflow region</a> to be extended
-	as would be required for ''align-content/end'' alignment
-	in the relevant axis.
+	in the relevant axis
+	however much would be required to satisfy ''align-content/end'' alignment
+	in that axis.
 	(In general, this means that the <a>scroll container</a>’s padding
 	is added to the bounding rectangle of its in-flow children.
 	See [[css-overflow-3]] for details.)