Link to `ayp.coffee` from the Hubot in README

It would be nice to link the [scripts/ayp.coffee](https://github.com/sshirokov/arrakis-hubot/blob/master/scripts/ayp.coffee) that builds the strips as well as [ayp-template-images](https://github.com/desert-planet/arrakis-hubot/tree/master/ayp-template-images) for the source images.

It would be nice to know at least with one click where the sausage is imported from
