Update changes section with change to 4.4.2.1

Author: shans

web-animations/index.html

@@ -7932,6 +7932,7 @@ <h2>Changes since last publication</h2>
             <a>spacing points</a>, and <a>point offsets</a> to <a>motion path
             animation effects</a> in order to support all the features of SVG's
             <code>animateMotion</code> element.
+        <li>Modified the <a>effective point offsets</a> formula to take into account negative offsets.
         <li>Removed custom effect priorities.
         <li>Renamed the <code>Timeline</code> interface to
             <a>AnimationTimeline</a>.