Add some links used by the coding standards

[ganto]

I renamed the ansible modules section to not overlap with the Ansible Modules link. Not sure if this is necessary. But there is still a somehow related(?) error building the policy.

[drybjed]

Not sure yet why the error is there. I'll merge this PR and re-run the test, let's see if it shows up again.

[ypid]

@ganto @drybjed Please note that changes should not go directly into the globa.rst file (I guess I failed to documented that here). The reason is that parts of global.rst are generated.

I updated the docs:

• https://github.com/debops/docs/issues/155
• https://debops-contrib.readthedocs.io/en/latest/adding-roles.html