Run your app's postinstall npm script during this package's postinstall script.

Yarn runs the postinstall script after yarn, yarn install and yarn add <package> but not after yarn remove <package>. If you add this package to your project, it will execute your project's postinstall hook even after a yarn remove <package>. This requires your postinstall script to be idempotent, because it will be run twice for yarn, yarn install, and yarn add <package>