Explain how to set production webpack alias in readme

[nickserv]

This part of the readme makes sense to me conceptually:

You probably don't want to call it if you're in production, and better yet, alias the module to nothing with webpack in production.

However, it's not clear to me where to find information in the webpack 2+ docs on how I can actually set an empty alias. Can we please either add a documentation/article link or a code snippet to the readme next to this? I would expect this to be used frequently.