Add varnishlogbeat and varnishstatbeat (elastic#4353)

libbeat/docs/communitybeats.asciidoc

@@ -62,6 +62,8 @@ 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/phenomenes/varnishlogbeat[varnishlogbeat]:: Reads log data from a Varnish instance and ships it to Elasticsearch.
+https://github.com/phenomenes/varnishstatbeat[varnishstatbeat]:: Reads stats data from a Varnish instance and ships it to Elasticsearch.
 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