[scroll-animations-1] Add more examples for animation-range shorthand. w3c#8438

Author: fantasai

scroll-animations-1/Overview.bs

@@ -952,10 +952,18 @@ spec: cssom-view-1; type: dfn;
 			animation-range-start: entry 0%;
 			animation-range-end: entry 100%;
 
+			animation-range: entry exit;
+			animation-range-start: entry 0%;
+			animation-range-end: exit 100%;
+
 			animation-range: 10%;
 			animation-range-start: 10%;
 			animation-range-end: normal;
 
+			animation-range: 10% 90%;
+			animation-range-start: 10%;
+			animation-range-end: 90%;
+
 			animation-range: entry 10% exit;
 			animation-range-start: entry 10%;
 			animation-range-end: exit 100%;