TBTF: In-context Framework Intro.

Henrik,

I've done an editing pass over the wording as we discussed on the TBTF call
yesterday, HTML'ised things and added the diagram to set things in-context
(I hope). I've added Doc Status and EdNotes with most of the major feedback
items that I could remember (I'm working from home today and I left my
scribblings at the office).

I've Cc'd the other TBTF members for visibility and I've also Cc'd the
public archive (only just discovered that there are both www-archive and
w3c-archive) in case we want to point at this stuff later.

Best regards

Stuart