fix: add NotificationProvider to App component

Author: hrhrng

src/App.tsx

@@ -1,7 +1,13 @@
 import { MainLayout } from '@components/Layout/MainLayout'
+import { NotificationProvider } from '@components/Notification/Notification'
 
 function App() {
-  return <MainLayout />
+  return (
+    <>
+      <MainLayout />
+      <NotificationProvider />
+    </>
+  )
 }
 
 export default App