MLE-24747 Small docs updates for versions

Not mentioning Confluent Platform versions anymore, so we don't have to be in the business of syncing with those. We just want to mention Kafka versions.

Author: rjrudin

docs/system-requirements.md

@@ -6,10 +6,7 @@ nav_order: 2
 
 The MarkLogic Kafka connector has the following system requirements:
 
-* Kafka 2.5 or higher, or Confluent Platform 7 or higher
+* For version 2.0.0 of the connector and higher, Kafka 4.0 or higher and Java 17 or higher are required.
+* For versions of the connector prior to 2.0.0, Kafka 2.5 or higher and Java 8 or higher are required.
 * For writing data, MarkLogic 9 or higher.
 * For reading data, MarkLogic 10.0-6 or higher.
-
-The MarkLogic Kafka connector may work on versions of Kafka prior to 2.5 or Confluent Platform prior to 7, but it has
-not been tested on those. 
-