Collatejson binary comparision documentation.

Change-Id: Ie29c99ff84da9d4bc558e6c199276547a4217821
Reviewed-on: http://review.couchbase.org/43355
Reviewed-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Tested-by: Pratap Chakravarthy <prataprc@couchbase.com>