[css-animations-2] Allow 'auto' for 'animation-duration' in 'animation' shorthand. w3c#8656

Author: fantasai

css-animations-2/Overview.bs

@@ -680,7 +680,7 @@ to the simultaneously-applied timeline specified in 'animation-timeline'.
 
 The 'animation' shorthand property syntax is as follows:
 
-<span class=prod><dfn>&lt;single-animation></dfn> = <<time [0s,∞]>> || <<easing-function>> || <<time>> || <<single-animation-iteration-count>> || <<single-animation-direction>> || <<single-animation-fill-mode>> || <<single-animation-play-state>> || [ none | <<keyframes-name>> ] || <<single-animation-timeline>></span>
+<span class=prod><dfn>&lt;single-animation></dfn> = <<'animation-duration'>> || <<easing-function>> || <<'animation-delay'>> || <<single-animation-iteration-count>> || <<single-animation-direction>> || <<single-animation-fill-mode>> || <<single-animation-play-state>> || [ none | <<keyframes-name>> ] || <<single-animation-timeline>></span>