add the movie_list script

movie_list/scroll-indicator.js

@@ -0,0 +1,11 @@
+(function() {
+  var si = document.querySelector(".scroll-indicator");
+  var onscroll = function() {
+    var max = document.body.scrollHeight - window.innerHeight;
+    si.style.display = "block";
+    si.style.width = (window.pageYOffset / max * 100) + "%";
+  };
+
+  window.onscroll = onscroll;
+  onscroll();
+})();