Updating the extensions doc

Author: hasani-h

articles/azure-arc/data/using-extensions-in-postgresql-server.md

@@ -14,9 +14,79 @@ ms.topic: how-to
 
 # Use PostgreSQL extensions in your Azure Arc-enabled PostgreSQL server
 
-Extensions are not currently supported in this preview.
+PostgreSQL is at its best when you use it with extensions.
+
+[!INCLUDE [azure-arc-data-preview](../../../includes/azure-arc-data-preview.md)]
+
+## Supported extensions
+For this preview, the following standard [`contrib`](https://www.postgresql.org/docs/14/contrib.html) extensions are already deployed in the containers of your Azure Arc-enabled PostgreSQL server:
+- adminpack
+- amcheck
+- autoinc
+- bloombtree_gin
+- btree_gist
+- citext
+- cube
+- dblink
+- dict_int
+- dict_xsyn
+- earthdistance
+- file_fdw
+- fuzzystrmatch
+- hstore
+- insert_username
+- intagg
+- intarray
+- isn
+- lo
+- ltree
+- moddatetime
+- old_snapshot
+- pageinspect
+- pg_buffercache
+- pg_freespacemap
+- pg_prewarm
+- pg_stat_statements
+- pg_surgery
+- pg_trgm
+- pg_visibility
+- pgcrypto
+- pgrowlocks
+- pgstattuple
+- postgres_fdw
+- refint
+- seg
+- sslinfo
+- tablefunc
+- tcn
+- tsm_system_rows
+- tsm_system_time
+- unaccent
+- xml2
+
+Updates to this list will be posted as it evolves over time.
+
+> [!IMPORTANT]
+> While you may bring to your server an extension other than those listed above, in this Preview, it will not be persisted to your system. It means that it will not be available after a restart of the system and you would need to bring it again.
+
+
+## Create extensions
+Connect to your server with the client tool of your choice and run the standard PostgreSQL query:
+```console
+CREATE EXTENSION <extension name>;
+```
+
+## Show the list of extensions created
+Connect to your server with the client tool of your choice and run the standard PostgreSQL query:
+```console
+select * from pg_extension;
+```
+
+## Drop an extension
+Connect to your server with the client tool of your choice and run the standard PostgreSQL query:
+```console
+drop extension <extension name>;
+```
 
 ## Next steps
-- Read documentation on [`plv8`](https://plv8.github.io/)
-- Read documentation on [`PostGIS`](https://postgis.net/)
-- Read documentation on [`pg_cron`](https://github.com/citusdata/pg_cron)
+- **Try it out.** Get started quickly with [Azure Arc Jumpstart](https://github.com/microsoft/azure_arc#azure-arc-enabled-data-services) on Azure Kubernetes Service (AKS), AWS Elastic Kubernetes Service (EKS), Google Cloud Kubernetes Engine (GKE) or in an Azure VM.