postgresql_privs: enhance type=table documentation (ansible-collections#892)

`type=table` in postgresql_privs can be used to manage view or materialized view privileges.

Make this behavior explicit in `postgresql_privs` in documentation.

See ansible-collections#841

Author: lalmeras

plugins/modules/postgresql_privs.py

@@ -48,7 +48,7 @@
     - The C(type) choice is available since Ansible version 2.10.
     - The C(procedure) is supported since collection version 1.3.0 and PostgreSQL 11.
     - The C(parameter) is supported since collection version 3.1.0 and PostgreSQL 15.
-    - The C(table) is inclusive of foreign tables since collection version 3.6.0.
+    - The C(table) also includes views and materialized views. It is inclusive of foreign tables since collection version 3.6.0.
     type: str
     default: table
     choices: [ database, default_privs, foreign_data_wrapper, foreign_server, function,