feat: add router

src/App.js

-import './App.css';
+import React from 'react';
+import { BrowserRouter, Routes, Route, Redirect } from 'react-router-dom';
+
 import Join from './pages/join';
 //import Schedule from './pages/mainAside';
-//import Login from './pages/login';
+import Login from './pages/login';
+import MySchedulerApp from './pages/main';
 
 function App() {
   return (
-    <div className="App">
-      <Join/>
-    </div>
+    <BrowserRouter>
+      <Routes>
+        <Route path="/" element={<MySchedulerApp/>} />
+        <Route path="/users/login" element={<Login/>} />
+        <Route path="/users" element={<Join />} />
+      </Routes>
+    </BrowserRouter>
   );
 }