Document the rebalance performance tuning options for Cruise Control when deployed to Streams on OCP. The supported options for Streams on OCP were added in ENTMQST-1950.

There are several performance options that can tune a rebalance. These include: concurrent_partition_movements_per_broker, concurrent_intra_partition_movements, concurrent_leader_movements and replication_throttle. These values can impact on how long rebalance takes and how stable a cluster will be during a rebalance so we should allow users to tune them.