Starting both client and server

package.json

{
  "name": "name-of-project",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "scripts": {
    "install-client":"yarn --cwd client install",
    "install-server":"yarn --cwd server install",
    "server": "yarn --cwd server run watch",
    "client": "yarn --cwd client start",
    "watch": "yarn run server & yarn run client",
    "test":"yarn --cwd serve run test && yarn --cwd client run test"
  }
}