Add react-ikonate as possible usage option in README

[danielkov]

Hello!

First of all great icon set. So great, that I decided to fork and create an easy to use solution for people using React.

I will try to keep it up to date with master on this repository. I gave you full credit for the icons in my README. Would you like to add my project to yours, so that people can see?

It is on NPM at react-ikonate