OARIS3 — Remove mandated approach to subsystem integration in 8.2

Section 8.2 mandates how topics and partitions should be used to include different subsystems into an OARIS based system.

However the approach mandated is not the only approach and other approaches may be used and be more suitable for a given use case. This section should be re-written to provide some guidance examples rather than mandates

Reword section 8.2

Reword section 8.2 to give guidance to a system integrator rather than mandate a particular approach.