add missing statement to find Lona in templates

Author: pfpulux

lona_bootstrap_5/templates/bootstrap_5/main.js

@@ -1,4 +1,5 @@
 // setup lona context ---------------------------------------------------------
+window.addEventListener('load', () => {
 var lona_context = new Lona.LonaContext({
     target: '#lona',
     title: '{{ settings.BOOTSTRAP_5_TITLE }}',
@@ -148,4 +149,5 @@ lona_context.add_message_handler(function(lona_context, raw_message) {
 });
 
 // init -----------------------------------------------------------------------
-lona_context.setup();
+lona_context.setup();
+});