Include pay with STEEM tutorials

[TimCliff]

I don't know if this is covered in any of the other planned issues, but it would be good to have info on how to add "Pay with STEEM" options to a website

Reference: https://steemit.com/steemdev/@adept/how-we-added-pay-with-steem-sbd-options-to-the-thesteemitshop-shopify-store-using-steem-connect

[relativityboy]

This looks interesting.