add link to jquery-thingy-picker

Hi Mike,

I as mentioned before, I needed a more generic version of the friend selector. I got to publish it now, though it's still a lot(!) of refinement to do.

However, since the generic version is actively used in a project of mine I will continue supporting it. I'd like to add a link to this repositories Readme for anyone interested. It contains an demo page on heroku with your FB example.

Let me know what you think.