set default_codec doc attribute

Author: jsvd

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 9.1.1
+  - Docs: Set the default_codec doc attribute.
+
 ## 9.1.0
   - Set number_of_shards to 1 and document_type to '_doc' for es 7.x clusters #741 #747
   - Fix usage of upsert and script when update action is interpolated #239

docs/index.asciidoc

@@ -1,5 +1,6 @@
 :plugin: elasticsearch
 :type: output
+:default_codec: plain
 
 ///////////////////////////////////////////
 START - GENERATED VARIABLES, DO NOT EDIT!
@@ -690,3 +691,5 @@ See also https://www.elastic.co/guide/en/elasticsearch/reference/current/docs-in
 
 [id="plugins-{type}s-{plugin}-common-options"]
 include::{include_path}/{type}.asciidoc[]
+
+:default_codec!:

logstash-output-elasticsearch.gemspec

@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name            = 'logstash-output-elasticsearch'
-  s.version         = '9.1.0'
+  s.version         = '9.1.1'
   s.licenses        = ['apache-2.0']
   s.summary         = "Stores logs in Elasticsearch"
   s.description     = "This gem is a Logstash plugin required to be installed on top of the Logstash core pipeline using $LS_HOME/bin/logstash-plugin install gemname. This gem is not a stand-alone program"