tags not supported by application groups

[ollylawrence]

Documentation link

https://github.com/PaloAltoNetworks/pan-os-ansible/blob/develop/plugins/modules/panos_application_group.py

Describe the problem

The documentation makes reference to tags however panos does support the use of tags for application groups.

Suggested fix

Remove tags from the documentation.

[ollylawrence]

Example.

"msg": "Failed create:  testing 123 -> tag unexpected here",