Introduction section is long

[tireddy2]

Comment from Tommy Jensen: the Introduction is very long. I don't think it's appropriate for it to formally define the RFC's actual mechanisms; you can probably cleanly cut/paste the majority of it into an implementation following the terminology. I get how the final paragraphs belong in the intro; maybe replace the middle with a reference and for the moment assert to the reader that all existing approaches today leave the user in the dark