Add observability platform Ansible project

Deploys the Grafana stack (Prometheus/Alertmanager/Loki/Tempo/Grafana with
Alloy as collector) and the ELK stack (Filebeat/Logstash/Elasticsearch/
Kibana) via Docker Compose on a target host. External to the application
repo, pre-built by the mentor.

ansible/requirements.yml

@@ -0,0 +1,7 @@
+---
+collections:
+  - name: community.docker
+    version: ">=4.0.0"
+  - name: ansible.posix
+    version: ">=2.0.0"
+