Dynamically load animations.

This makes sure that we don't have to serve the open animation when the bar is actually closed.

src/index.js

@@ -1,12 +1,14 @@
 import "./style.scss";
-import {startClosedAnimation} from "./closed";
-import {startOpenAnimation} from "./open";
 
 window.addEventListener('load', function () {
     if (document.body.classList.contains('open')) {
-        startOpenAnimation();
+        import("./open").then(function (module) {
+            module.startOpenAnimation();
+        });
     } else {
-        startClosedAnimation();
+        import("./closed").then(function (module) {
+            module.startClosedAnimation();
+        });
     }
 
     doIfAuthorized(showToggleButton);