[css-animations-2] initial value of the exit ranges is 'auto', to match the start ranges (copypaste error)

Author: tabatkins

css-animations-2/Overview.bs

@@ -1014,7 +1014,7 @@ The behavior of 'timeline-trigger-exit-range' is defined in [[web-animations-2#t
 <pre class="propdef">
 Name: timeline-trigger-exit-range-start, timeline-trigger-exit-range-end
 Value: [ auto | normal | <<length-percentage>> | <<timeline-range-name>> <<length-percentage>>? ]#
-Initial: normal
+Initial: auto
 Applies to: all elements
 Inherited: no
 Percentages: relative to the specified [=named timeline range=] if one was specified, else to the entire timeline