[css-scroll-snap] Define handling of scroll-snap-points: repeat() when last repetition doesn't perfectly align to end edge of scrollable area.

Author: fantasai

css-scroll-snap/Overview.bs

@@ -375,7 +375,11 @@ Scroll Snapping Coordinates: the 'scroll-snap-points-x' and 'scroll-snap-points-
 			Defines start-<a href="#scroll-snap-alignment">aligned</a> <a>snap areas</a>
 			that span the <a>scrollable area</a> in the appropriate axis,
 			starting from the <a>start</a> edge of the <a>scrollable area</a>
-			and spanning across every <<length>> throughout the <a>scrollable area</a>.
+			and spanning every <<length>> across the entire <a>scrollable area</a>,
+			with the end edge of the last <a>snap area</a> occuring at or past the end edge of the <a>scrollable area</a>.
+			<span class="note">Note that the last <a>snap position</a>
+			effectively gets pulled into the scrollable area as necessary
+			to prevent overscrolling, see [[#choosing]].</span>
 
 			Negative values are invalid.
 			User agents must define a UA-defined minimum <<length>> greater than 0