Documentation of replication needs to make it clear that target drive for file replication should be network mounted

The replication documentation does not make it clear that the target directory for replication needs to be locally available on the machine where replication is run using file replication. There is no reason for anyone to assume this is the case. The docs make it clear rsync is used, and rsync works over a network.

We need to clearly state this requirement in the prerequisites for replication.