Remove References to "CHP"

[edjez]

The document seems to make a few references to "CHP" content, documentation and backstory.

We should aim to define the appropriate few terms that are needed locally - HIX, actor/role, etc- and document the few required interactions locally, since the references to other docs seem not to add value.

[edjez]

Been done - ready to close.

[mberg]

merged in thanks ed