feat: add/remove listener

Author: PatrickJS

src/index.ts

@@ -5,7 +5,11 @@
 export function bootloader (main): void {
   switch (document.readyState) {
     case 'loading':
-      document.addEventListener('DOMContentLoaded', () => main());
+      function _domReadyHandler() {
+        document.removeEventListener('DOMContentLoaded', _domReadyHandler, false);
+        main();
+      }
+      document.addEventListener('DOMContentLoaded', _domReadyHandler, false);
       break;
     case 'interactive':
     case 'complete':