Avdi's new null object gem (avdi/naught)

Since this is based on Avdi's pattern, would it be worth mentioning the https://github.com/avdi/naught gem that he just released to implement the null object pattern? If you think that's appropriate, I'd be willing to write a pull request that notes this in the README if you're too busy.

Despite the existence of naught, it's important that this gem at least stick around for existing users. Thanks for writing it.