add basic infrastructure of javascript example

example/provider/javascript/js/startup.js

@@ -0,0 +1,26 @@
+
+import { Webfuse } from "./webfuse/webfuse.js";
+import { StaticFileSystem } from "./static_filesystem.js";
+
+let webfuse = null;
+const filesystem = new StaticFileSystem(new Map([
+    ["/foo", "foo"],
+    ["/bar", "foo"]
+]));
+
+function onConnectButtonClicked() {
+    if (webfuse) { webfuse.close(); }
+
+    const urlTextfield = document.querySelector('#url');
+    const url = urlTextfield.value;
+    console.log(url);
+
+    webfuse = new Webfuse(url, filesystem);
+}
+
+function startup() {
+    const connectButton = document.querySelector('#connect');
+    connectButton.addEventListener('click', onConnectButtonClicked);
+}
+
+document.addEventListener('DOMContentLoaded', startup(),false);