- add: frontend webpage for login/register

frontend/src/App.js

@@ -0,0 +1,18 @@
+import React from "react";
+import { BrowserRouter as Router, Routes, Route } from "react-router-dom";
+import LoginPage from "./components/LoginPage";
+import RegisterPage from "./components/RegisterPage";
+
+const App = () => {
+    return (
+        <Router>
+            <Routes>
+                <Route path="/login" element={<LoginPage />} />
+                <Route path="/register" element={<RegisterPage />} />
+                <Route path="/" element={<h1>Welcome to the Game!</h1>} />
+            </Routes>
+        </Router>
+    );
+};
+
+export default App;