[scroll-animations-1] Define interaction of iteration-count with absolute keyframes w3c#8233

Author: fantasai

scroll-animations-1/Overview.bs

@@ -703,6 +703,15 @@ spec: cssom-view-1; type: dfn;
 	and the resulting [=active duration=]--
 	will be zero.
 
+	Animations that include absolutely-positioned keyframes
+	(those pinned to a specific point on the timeline,
+	e.g. using [[#named-range-keyframes|named timeline range keyframe selectors]] in ''@keyframes'')
+	are assumed to have an [=iteration count=] of 1
+	for the purpose of finding those keyframes’ positions
+	relative to 0% and 100%;
+	the entire animation is then scaled to fit the [=iteration duration=]
+	and repeated for each iteration.
+
 ## Named Timeline Scoping ## {#timeline-scope}
 
 	A named [=scroll progress timeline=] or [=view progress timeline=]