message: npm dev install typescript and ts-loader
diff: "babel-loader": "^8.1.0",
  "css-loader": "^3.6.0",
  "eslint": "^7.3.1",
  + "ts-loader": "^7.0.5",
  + "typescript": "^3.9.6",
  "webpack": "^4.43.0",
  "webpack-chrome-extension-reloader": "^1.3.0",
  "webpack-cli": "^3.3.12"
  