refactor: move Ansible roles to standard ansible/roles/ location

ansible/roles/observer/files/prometheus_alerts_rules.yml

@@ -0,0 +1,11 @@
+groups:
+- name: AllInstances
+  rules:
+  - alert: InstanceDown
+    expr: up == 0
+    for: 1m
+    annotations:
+      title: 'Instance {{ $labels.instance }} down'
+      description: '{{ $labels.instance }} of job {{ $labels.job }} has been down for more than 1 minute.'
+    labels:
+      severity: 'critical'