feat(logs/logstash): adding the logstash configuration

logs/logstash/pipeline/logstash.conf

@@ -0,0 +1,22 @@
+input {
+  gelf {
+    port => 12201
+  }
+}
+
+filter {
+  mutate {
+    rename => { "[full_message]" => "message" }
+  }
+}
+
+output {
+  elasticsearch {
+    hosts => ["http://elasticsearch:9200"]
+    index => "docker-%{[container_name]}-%{+YYYY.MM.dd}"
+  }
+
+  stdout {
+    codec => rubydebug
+  }
+}