Fix KafkaSource and KafkaSink example configurations in the user guide
Fix KafkaSource and KafkaSink example configurations in the user guide

This closes #86

Reviewers: Jeff Holoman, Denes Arvay

(Attila Simon via Bessenyei Balázs Donát)

szaboferee/flume,iaiengxia/flume,iaiengxia/flume,tmgstevens/flume,szaboferee/flume,tmgstevens/flume,tinawenqiao/flume,iaiengxia/flume,tinawenqiao/flume,tinawenqiao/flume,tmgstevens/flume,tinawenqiao/flume,szaboferee/flume,iaiengxia/flume,szaboferee/flume,tmgstevens/flume