Provide example for Logstash grok-filter plus Kibana dashboard

[Filebeat](https://www.elastic.co/guide/en/beats/filebeat/current/configuration-filebeat-options.html) and [Ingest](https://www.elastic.co/guide/en/elasticsearch/reference/master/grok-processor.html) might not be enough to replace [Logstash](https://www.elastic.co/guide/en/logstash/current/plugins-filters-grok.html) yet. Let's check on this.