Updated the correct doc for Kafka Consumer
Updated the correct doc for Kafka Consumer

Updated the correct doc for Kafka Consumer with link to latest repository.

Closes #14634

baishuo/elasticsearch_v2.1.0-baishuo,baishuo/elasticsearch_v2.1.0-baishuo,baishuo/elasticsearch_v2.1.0-baishuo,baishuo/elasticsearch_v2.1.0-baishuo,baishuo/elasticsearch_v2.1.0-baishuo,baishuo/elasticsearch_v2.1.0-baishuo,baishuo/elasticsearch_v2.1.0-baishuo