add: boilerplate w/ navbar, tailwindcss

frontend/src/router.jsx

@@ -0,0 +1,29 @@
+// router.jsx
+import { createBrowserRouter } from "react-router-dom";
+import App from "./App";
+import Main from "./pages/main";
+import Scenario from "./pages/scenario";
+import About from "./pages/about";
+const router = createBrowserRouter([
+  {
+    path: "/",
+    element: <App />,
+    children: [
+      {
+        index: true,
+        element: <Main />,
+      },
+      {
+        path: 'scenario/',
+        element: <Scenario />
+      },
+      {
+        path: 'about/',
+        element: <About />
+      }
+      
+    ],
+  },
+]);
+
+export default router;