link tag and payment pointers

Purpose
Overview of how the <link> tag and payment pointers work.
Sources
Payment Pointers syntax resolution
Payment Pointer Overview
Technical contact
Alex (+ Marcos for tag)

One-paragrph summary

Issue about multiple pointers

payment pointer are like DNS. arranges SPSP

payment pointer points to JSON file with address, which may change.

SPSP does roughly the same as IP. Sends packages to address specified in JSON.