u4

package.json

@@ -6,6 +6,7 @@
     "@testing-library/jest-dom": "^5.11.4",
     "@testing-library/react": "^11.1.0",
     "@testing-library/user-event": "^12.1.10",
+    "lint": "tslint -p tsconfig.json -c tslint.json",
     "react": "^17.0.1",
     "react-dom": "^17.0.1",
     "react-scripts": "4.0.3",