How to make NPM package like nodemon

I made a package for myself which merges multiple files to single file before starting server. Now I want to publish this package to npmjs.com but this package will not be used in the app like const mergeFiles = require('mergeFiles'). This package will be used more likely nodemon package so people will be able to call my package like node mergeFiles && node server with npm start command. Tutorials always show how to make it with require style so it doesn't work for me.