implemented pdf viewer functionality.

src/main.jsx

@@ -3,14 +3,16 @@ import { createRoot } from "react-dom/client";
 import { BrowserRouter as Router, Routes, Route } from "react-router";
 import App from "./App.jsx";
 import Resume from "./Resume.jsx";
+import PageNotFound from "./PageNotFound.jsx";
 
 const container = document.getElementById("app");
 const root = createRoot(container); // createRoot(container!) if you use TypeScript
 root.render(
   <Router>
     <Routes>
-      <Route path="/" element={<App />} />
-      <Route path="/resume" element={<Resume />} />
+      <Route exact path="/" element={<App />} />
+      <Route exact path="/resume" element={<Resume />} />
+      <Route path="*" element={<PageNotFound />} />
     </Routes>
   </Router>,
 );