Mojaloop: Document bulk payment/transfers pre-processing capability in Payment Hub

[edcable]

We recognize and understand that a lot of the scope of the bulk payment will actually fall outside of the scope of the central switch. We should fully document the proposed boundary of functionality in terms of DFSP pre-processing that the Payment Hub EE would handle - we should document both the requirements at the Payment Hub EE as well as requirements through web/online banking channel for the customer of the DFSP.

Even if we don't have time to fully implement this, I want this documented and part of the roadmap.