Add argument specs for roles

[robin-checkmk]

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Issue Number: #693

What is the new behavior?

We now include meta/argument_specs.yml with our roles.
This makes sure, the right variables are set at execution time.
Read these, for further information:

• https://docs.ansible.com/ansible/latest/dev_guide/developing_collections_documenting.html
• https://docs.ansible.com/ansible/latest/playbook_guide/playbooks_reuse_roles.html#role-argument-spec

Other information