message: feat: add watch:browser
diff: "test:lint": "tslint --project . && prettier \"src/**/*.ts\" --list-different",
  "test:unit": "nyc --silent ava",
  "watch": "run-s clean build:main && run-p \"build:main -- -w\"",
  + "watch:browser": "run-s clean build:browser && run-p \"build:browser -- -w\"",
  "cov": "run-s build test:unit cov:html && open-cli coverage/index.html",
  "cov:html": "nyc report --reporter=html",
  "cov:send": "nyc report --reporter=lcov && codecov",
  