fix(template): correct yarn start script for webpack projects

Author: djcsdy

template/template/package.json

@@ -12,7 +12,7 @@
   "scripts": {
     "build": "webpack --env.production",
     "prepare": "tsc",
-    "start": "webpack-dev-server --open",
+    "start": "webpack serve --open",
     "test": "ava",
     "lint": "eslint . && prettier --check .",
     "fix": "eslint . --fix && prettier --write .",