Update index.asciidoc

Author: ebuildy

docs/index.asciidoc

@@ -238,7 +238,7 @@ Elasticsearch with the same ID.
   * There is no default value for this setting.
   * This option is deprecated
 
-Note: This option is deprecated due to the https://www.elastic.co/guide/en/elasticsearch/reference/6.0/removal-of-types.html[removal of types in Logstash 6.0].
+Note: This option is deprecated due to the https://www.elastic.co/guide/en/elasticsearch/reference/6.0/removal-of-types.html[removal of types in Elasticsearch 6.0].
 It will be removed in the next major version of Logstash.
 This sets the document type to write events to. Generally you should try to write only
 similar events to the same 'type'. String expansion `%{foo}` works here.