README.md in fluent-plugin-elastic-log-0.4.1 vs README.md in fluent-plugin-elastic-log-0.4.2

@@ -1,41 +1,66 @@
 # fluent-plugin-elastic-log
 
-[Fluentd](https://fluentd.org/) filter plugin to do something.
+[Fluentd](https://fluentd.org/) filter plugin to process elastic logs.
 
-TODO: write description for you plugin.
+## plugins
 
-## Installation
+### out - elastic_audit_log_metric
 
-### RubyGems
+process audit logs and transform to metrics.
 
+Example:
+
+``` conf
+<match my_tag_pattern>
+  @type elastic_audit_log_metric
+
+  tag elastic_audit_log_metric
+  timestamp_key timestamp
+  timestamp_format epochmillis
+  prefix tags_
+</match>
 ```
-$ gem install fluent-plugin-elastic-log
-```
 
-### Bundler
+parameters are:
+* tag : Tag to emit metric events
 
-Add following line to your Gemfile:
+parameters for input record:
+* categories: Categories selected to be converted to metrics
+* category_key: Category key in input record
+* layer_key: Layer key in input record
+* request_type_key: Request type key in input record
+* cluster_key: Cluster key in input record
+* user_key: Request user key in input record
+* indices_key: Indices key in input record
+* r_indices_key: Resolved indices key in input record
+* timestamp_key: Timestamp key in input record
+* privilege_key: Request privilege key in input record
 
-```ruby
-gem "fluent-plugin-elastic-log"
-```
+parameters for output metric:
+* timestamp_format: Timestamp format (iso, epochmillis, epochmillis_str)
+* prefix: Attribute prefix for output metric
+* aggregate_ilm: Aggregate ILM on resolved indices
 
-And then execute:
+More details from the
+[elastic_audit_log_metric output plugin code](lib/fluent/plugin/out_elastic_audit_log_metric.rb#L49)
 
-```
-$ bundle
-```
+## Installation
 
-## Configuration
 
-You can generate configuration template:
+Manual install, by executing:
 
-```
-$ fluent-plugin-config-format filter elastic-log
-```
+    $ gem install fluent-plugin-elastic-log
 
-You can copy and paste generated documents here.
+Add to Gemfile with:
+
+    $ bundle add fluent-plugin-elastic-log
+
+## Compatibility
+
+plugin in 1.x.x will work with:
+- ruby >= 2.4.10
+- td-agent >= 3.8.1-0
 
 ## Copyright
 
 * Copyright(c) 2023- Thomas Tych
 * License