using the wiki to interate on definitions

We have a number of definitions which are *almost* defined but not quite
nailed down

I suggest using the wiki as a place where we can iterate on definitions of
things like WebID and so on, based on ongoing discussions and clarifications

This is useful because

1. It provides a stable URI for defining WebID etc.
2. it allows ephemeral conversations to have a context and improve the
working definitions
3. the WebID CG should be the place where a webid is defined
4. Examples and other things like can back up the definitions
5. Iterating on Github PRs may be at this point taking on too much and
tough to gain full consensus on the little details

Once these definitions have sufficient contentions all specs implementing
WebID can proceed, based on a common understanding.

New specs in and outside th group can be made quickly and consistently
using agreed upon text

Any thoughts on this approach?