message: Readme: Update Content section
diff: @@ -29,6 +29,7 @@ into Rust structures.
  * [SELECT query (mapping results)](#select-query-mapping-results)
  * [PREPARE and EXECUTE query](#prepare-and-execute-a-query)
  * [Listen to server events](#listen-to-server-events)
  +* [Cassandra clusters and load balancing](#cassandra-clusters-and-load-balancing)
  * [Supported features](#supported-features)
  