Add '.io' as a startup name suffix?

Thank you for building this!! It's amazing.

My suggestion is to add '.io' as a startup name suffix [in the appropriate generator function](https://github.com/shadowfiles/startup/blob/master/js/generators.js#L215). [Lots of company names](https://www.quora.com/Which-Companies-use-io-Domains) follow the pattern "<noun>.io", and many of them could have come from your generator :D
