49 cqlreplicator on glue add support for deletes

[nwheeler81]

Issue #, if available:

Fixed #79

Description of changes: Updated README.MD

• added support for DELETEs for Amazon Keyspaces use-case
• reduced the replication lag from 60s to 30s
• replaced MEMORY_AND_DISK strategy to DISK_ONLY
• optimized the primary keys read path

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[nwheeler81]

Fixed https://github.com/aws-samples/cql-replicator/issues/#88