wip: add monitoring configs

group_vars/gateways.yml

hosts.yml

playbook.yml

roles/services/files/authorized_keys

roles/services/files/etc/apt/sources.list

roles/services/files/etc/cron.d/update-apt-list

roles/services/files/etc/motd

roles/services/files/etc/resolv.conf

roles/services/files/grafana.list

roles/services/files/prometheus/first_rules.yml

roles/services/files/prometheus/prometheus.yml

roles/services/tasks/base.yml

roles/services/tasks/main.yml

roles/services/tasks/monitoring.yml

roles/services/tasks/software.yml