Add note about where to get MC and how we use it
Add note about where to get MC and how we use it

joekiller/logstash-kafka,tinglinux/logstash-kafka,Aloomaio/logstash-kafka,Aloomaio/logstash-kafka,tinglinux/logstash-kafka,joekiller/logstash-kafka,opentable/logstash-kafka,opentable/logstash-kafka