add kafkabeat (elastic#4017)

* add  kafkabeat

kafkabeat read data from kafka

* Update communitybeats.asciidoc

libbeat/docs/communitybeats.asciidoc

@@ -32,6 +32,7 @@ https://github.com/icinga/icingabeat[icingabeat]:: Icingabeat ships events and s
 https://github.com/devopsmakers/iobeat[iobeat]:: Reads IO stats from /proc/diskstats on Linux.
 https://github.com/radoondas/jmxproxybeat[jmxproxybeat]:: Reads Tomcat JMX metrics exposed over 'JMX Proxy Servlet' to HTTP.
 https://github.com/mheese/journalbeat[journalbeat]:: Used for log shipping from systemd/journald based Linux systems.
+https://github.com/dearcode/kafkabeat[kafkabeat]:: read data from kafka with Consumer-groups. 
 https://github.com/eskibars/lmsensorsbeat[lmsensorsbeat]:: Collects data from lm-sensors (such as CPU temperatures, fan speeds, and voltages from i2c and smbus).
 https://github.com/consulthys/logstashbeat[logstashbeat]:: Collects data from Logstash monitoring API (v5 onwards) and indexes them in Elasticsearch.
 https://github.com/yedamao/mcqbeat[mcqbeat]:: Reads the status of queues from memcacheq.
@@ -59,7 +60,7 @@ https://github.com/hartfordfive/udplogbeat[udplogbeat]:: Accept events via local
 https://github.com/cleesmith/unifiedbeat[unifiedbeat]:: Reads records from Unified2 binary files generated by
 network intrusion detection software and indexes the records in Elasticsearch.
 https://github.com/mrkschan/uwsgibeat[uwsgibeat]:: Reads stats from uWSGI.
-https://github.com/eskibars/wmibeat[wmibeat]:: Uses WMI to grab your favorite, configurable Windows metrics.
+https://github.com/eskibars/wmibeat[wmibeat]:: Uses WMI to grab your favorite, configurable Windows metrics. 
 
 
 Have you created a Beat that's not listed? If so, add the name and description of your Beat to the source document for