Update Ansible groups documentation

docs/_static/ansible/create_ansible_group_of_groups.png

docs/_static/ansible/create_ansible_network_group.png

docs/_static/ansible/edit_ansible_group.png

docs/_static/ansible/edit_ansible_host_vars.png

docs/_static/ansible/list_ansible_groups.png

docs/_static/ansible/register_ansible_group.png

docs/_static/ansible/view_ansible_network_group.png

docs/network.rst