Remove outdated trigger syntax from example

Author: majido

scroll-animations-1/Overview.bs

@@ -655,11 +655,8 @@ following effects:
           easing: "linear"
         });
       let timeline = new ScrollTimeline({
-        trigger: new ScrollTrigger({
-          scrollSource: document.documentElement,
-          orientation: "vertical",
-          kind: "range"
-        });
+        scrollSource: document.documentElement,
+        orientation: "vertical",
       });
       let animation = new Animation(effect, timeline);
       animation.play();