Add icingabeat to the list (#3774)

libbeat/docs/communitybeats.asciidoc

@@ -28,6 +28,7 @@ https://github.com/YaSuenag/hsbeat[hsbeat]:: Reads all performance counters in J
 https://github.com/christiangalsterer/httpbeat[httpbeat]:: Polls multiple HTTP(S) endpoints and sends the data to
 Logstash or Elasticsearch. Supports all HTTP methods and proxies.
 https://github.com/jasperla/hwsensorsbeat[hwsensorsbeat]:: Reads sensors information from OpenBSD.
+https://github.com/icinga/icingabeat[icingabeat]:: Icingabeat ships events and states from Icinga 2 to Elasticsearch or Logstash.
 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.