use optimized code for fetching

js/main.js

@@ -2,7 +2,7 @@
 if ("serviceWorker" in navigator) {
   window.addEventListener("load", () => {
     navigator.serviceWorker
-      .register('https://siddharthdhirde.github.io/busNoticeBoard/sw_cached_pages.js')
+      .register('https://siddharthdhirde.github.io/busNoticeBoard/sw_cached_site.js')
       .then((reg) => console.log("ServiceWorker registered successfully"))
       .catch((err) => console.log(`ServiceWorker registration failed: ${err}`));
   });