Add a license

[notpushkin]

Hey there, fellow HN reader here. Thanks for sharing this! Hopefully it will help many people :-)

I've noticed this repo lacks a LICENSE file, which is the usual way of specifying the project's license. This means the project is not licensed / non-open source, and people can't use it legally. Could you pick a license and add it to the repo? Let me know if you need any help with that!