Add protocol for verification via social media and personal websites

It's important to have a specified method of verifying OneName ownership via social media and personal websites. Without a single way of verifying ownership, it is impossible for crawlers to know whether or not a post actually does what it claims to do (in this case, providing verification of OneName ownership).

By specifying what to put in the post, such as "onename-username", a crawler can simply load the proof URL and search for the required text.