Merge branch 'vmalert' into 'master'

pica-metrologie/README.md

pica-metrologie/alertmanager/Dockerfile

pica-metrologie/alertmanager/alertmanager.yml

pica-metrologie/alertmanager/entrypoint.sh

pica-metrologie/alertmanager/templates.tpl

pica-metrologie/blackbox.yml

pica-metrologie/docker-compose.yml

pica-metrologie/secrets/alertmanager.secrets.example

pica-metrologie/secrets/exporters-auth.secrets.example

pica-metrologie/vmagent-prom.yml

pica-metrologie/vmalert-rules.yml