[css-animations][bikeshed] Fix ambiguous <time> ref warning

Author: Sylvain Galineau

css-animations/Overview.bs

@@ -17,6 +17,7 @@ Former Editor: Chris Marrin, Apple Inc.
 
 Abstract: This CSS module describes a way for authors to animate the values of CSS properties over time, using keyframes. The behavior of these keyframe animations can be controlled by specifying their duration, number of repeats, and repeating behavior. 
 
+Link Defaults: css-values-3 (type) <time>
 Ignored Terms: domstring, float, animationeventinit, eventinit, eventtarget, document
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