added type definition of react-router-dom

Author: NileshPatel17

packages/app/package.json

@@ -238,6 +238,7 @@
     "@types/react": "^16.8.12",
     "@types/react-dom": "^16.8.3",
     "@types/react-icons": "2.2.7",
+    "@types/react-router-dom": "^4.3.1",
     "@types/react-stripe-elements": "^1.3.2",
     "@types/resolve": "^0.0.8",
     "@types/socket.io-client": "^1.4.32",