[css-animations-2] Default composit should be 'animation-composition'.

Author: fantasai

css-animations-2/Overview.bs

@@ -278,7 +278,8 @@ its associated [=keyframes=] are generated as follows:
     *   Let |default timing function| be the corresponding [=computed value=]
         of 'animation-timing-function' on |element|.
 
-    *   Let |default composite| be ''replace''.
+    *   Let |default composite| be the corresponding [=computed value=]
+        of 'animation-composition' on |element|.
 
     *   Let |keyframes| be an empty sequence of [=keyframe=] objects,
         each possessing a