新版的create-react-app孕蝉，如果你之前在電腦安裝過全局create-react-app就會出現(xiàn)項目不全的問題
A template was not provided. This is likely because you're using an outdated version of create-react-app. Please note that global installs of create-react-app are no longer supported.
解決方案：
卸載
npm uninstall -g create-react-app
如果上面不能卸載可以用下面方法
yarn global remove create-react-app
卸載完捍壤，然后再用
npx create-react-app [project-name]
就可以了
