Update communitybeats.asciidoc (#8439)

Add statsdbeat

libbeat/docs/communitybeats.asciidoc

@@ -91,6 +91,7 @@ https://github.com/martinhoefling/saltbeat[saltbeat]:: Reads events from salt ma
 https://github.com/benben/serialbeat[serialbeat]:: Reads from a serial device.
 https://github.com/consulthys/springbeat[springbeat]:: Collects health and metrics data from Spring Boot applications running with the actuator module.
 https://github.com/philkra/springboot2beat[springboot2beat]:: Query and accumulate all metrics endpoints of a Spring Boot 2 web app via the web channel, leveraging the http://micrometer.io/[mircometer.io] metrics facade.
+https://github.com/sentient/statsdbeat[statsdbeat]:: Receives UDP https://github.com/etsy/statsd/wiki[statsd] events from a statsd client.
 https://github.com/berfinsari/tracebeat[tracebeat]:: Reads traceroute output and indexes them into Elasticsearch.
 https://github.com/buehler/go-elastic-twitterbeat[twitterbeat]:: Reads tweets for specified screen names.
 https://github.com/gravitational/udpbeat[udpbeat]:: Ships structured logs via UDP.