"devDependencies": {
    "@types/styled-components": "^5.1.1",
    "@typescript-eslint/eslint-plugin": "^3.6.0",
    "@typescript-eslint/parser": "^3.6.0",
    "eslint": "6.8.0",
    "eslint-config-airbnb": "^18.2.0",
    "eslint-config-prettier": "^6.11.0",
    "eslint-import-resolver-typescript": "^2.0.0",
    "eslint-plugin-import": "^2.22.0",
    "eslint-plugin-jsx-a11y": "^6.3.1",
    "eslint-plugin-prettier": "^3.1.4",
    "eslint-plugin-react": "7.20.0",
    "prettier": "^2.0.5"
  }



  put those dependencies in devDependencies in your package.json and run yarn. i dont know why
  devdependencies are ignored by CRA. :)