server documentation should cover Carrier Publication (a.k.a. CCCP)

Since www.couchbase.com/wiki was decommissioned, a number of things aren't well documented publicly any longer.   One of these is Carrier Publication (a.k.a. CCCP).

Docs should be added to the public documentation on the concept, how it works, public interfaces, etc.  The SDKs use and have tuneables around this functionality, but it's really core server functionality that needs to be documented.

I will comment on where some details can be found.

Note that I originally gave this the project name of CCCP in a tradition of having fun project names.  I believe the public name of it should now be "Carrier Publication".