Recommend using NetworkTopologyStrategy with Scylla

[pdbossman]

Hello,
Scylla readme contains:
cqlsh> create keyspace ycsb WITH REPLICATION = {'class' : 'SimpleStrategy', 'replication_factor': 3 };

SimpleStrategy is not recommended, NetworkTopologyStrategy is recommended.

Recommend changing this to:
CREATE KEYSPACE ycsb WITH replication = {'class': 'NetworkTopologyStrategy', 'YOUR-DATACENTER-HERE': '3'} AND durable_writes = true;