add hdfs

Author: maltesander

docs/modules/opa/pages/index.adoc

@@ -50,6 +50,7 @@ Currently the following products on the Stackable Data Platform support policy d
 
 * xref:airflow:usage-guide/security.adoc#_open_policy_agent[Apache Airflow]
 * xref:druid:usage-guide/security.adoc#_authorization_with_open_policy_agent_opa[Apache Druid]
+* xref:hdfs:usage-guide/security.adoc#_authorization[Apache Hadoop/HDFS]
 * xref:kafka:usage-guide/security.adoc#_authorization[Apache Kafka]
 * xref:superset:usage-guide/security.adoc#_opa_role_mapping[Apache Superset]
 * xref:trino:usage-guide/security.adoc#_authorization[Trino]