Format observer configuration for better readability

Jellyfin.Plugin.Seasonals/Web/cherryblossom.js

@@ -33,7 +33,11 @@ function toggleCherryBlossom() {
 }
 
 const observer = new MutationObserver(toggleCherryBlossom);
-observer.observe(document.body, { childList: true, subtree: true, attributes: true });
+observer.observe(document.body, {
+  childList: true,
+  subtree: true,
+  attributes: true
+});
 
 function createPetal(container) {
     const petal = document.createElement('div');