npm 的主要功能
- 下载别人编写的第三方包到本地使用
 - 下载并安装别人编写的 CLI 到本地使用
 - 将自己编写的包或命令行程序发布到 npm上
 
package.json优化
- 上线精简 devpendenciespeer & Devpendencies
 - 把上线依赖的,移动到开发依赖
 
{  "name": "webpack-demo",  "version": "1.0.0",  "private": true, // 私有仓库  "main": "src/index.js", // 向外暴露的 js入口文件  "scripts": {    "start": "npx webpack",    "build": "echo \"Error: no test specified\" && exit 1",    "test": "echo \"Error: no test specified\" && exit 1"  },  "dependencies": {},  "devDependencies": {    "cross-env": "^7.0.3",    "webpack": "^5.73.0",    "webpack-cli": "^4.10.0"  },  "description": "项目描述",  "keywords": ["项目关键词"],  "author": "",  "license": "MIT"}