connectivity: document how to test postgresql manually

Change-Id: I16f091b35a8246cb43842a6b864ba6061013ea7a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/109695
Tested-by: Michael Stahl <michael.stahl@allotropia.de>
Reviewed-by: Michael Stahl <michael.stahl@allotropia.de>

connectivity/README

@@ -2,6 +2,26 @@ Contains database pieces, drivers, etc.
 
 [[dbaccess]] builds UI on top of this.
 
+=== PostgreSQL ===
+
+For testing, use:
+
+podman pull postgres:latest
+podman run --name=postgres -e POSTGRES_PASSWORD=foobarbaz -p 127.0.0.1:5432:5432 postgres:latest
+
+In Base, Connect to an existing database, select PostgreSQL:
+
+URL: host=127.0.0.1 port=5432 dbname=postgres
+User: postgres
+Password: foobarbaz
+
+podman stop postgres
+podman rm postgres
+
+In order to test SCRAM authentication, create the container like this:
+
+podman run --name=postgres -e POSTGRES_PASSWORD=foobarbaz -e POSTGRES_INITDB_ARGS=--auth-host=scram-sha-256 -e POSTGRES_HOST_AUTH_METHOD=scram-sha-256 -p 127.0.0.1:5432:5432 postgres:latest
+
 === mysql_test ===
 
 - The CppunitTest_mysql_test unit test can be used to test the mysqlc