Folder and file structure

The following folder structure only shows the files that are relevant for the MERN skeleton backend. With these files, we will produce a functioning, standalone server-side application: 

| mern_skeleton/
   | -- config/
      | --- config.js
   | -- server/
      | --- controllers/
         | ---- auth.controller.js
         | ---- user.controller.js
      | --- helpers/
         | ---- dbErrorHandler.js
      | --- models/
         | ---- user.model.js
      | --- routes/
         | ---- auth.routes.js
         | ---- user.routes.js
      | --- express.js
      | --- server.js
  | -- .babelrc
  | -- nodemon.json
  | -- package.json
  | -- template.js
  | -- webpack.config.server.js

This structure will be further expanded in the next chapter, where we complete the skeleton application by adding a React frontend.