rewrite readme requirements and versions paragraphs

Zastąpienie paragrafów requirements i packages przez uzgodniony wspólny format:

## Supported environments

* Python 2 on `CentOS 7`
* Python 2 on `Ubuntu Focal`

## Versions

* `containers.projects.task.gda.pl/containers/ansible 22.03-ansible-2.9.27-python2`

Role is tested by running in Docker container. The container (specified above) contains all dependencies necessary for running this role.
If you want to use this role you should use our Docker container or ensure that all packages required to run this role are installed on
your host in the same versions as in the container.

EDIT: Aktualna konwencja zgodnie z wzorcowym: filesystem!54 (merged)