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

ansible/roles/observer/files/prometheus_main.yml

@@ -0,0 +1,28 @@
+global:
+    scrape_interval: 15s
+
+scrape_configs:
+    - job_name: prometheus
+      scrape_interval: 30s
+      static_configs:
+          - targets: ["localhost:9090"]
+
+    - job_name: node-exporter
+      scrape_interval: 30s
+      static_configs:
+          - targets:
+                ["192.168.0.1:9100", "192.168.0.10:9100", "192.168.0.11:9100"]
+
+    - job_name: cadvisor
+      scrape_interval: 30s
+      static_configs:
+          - targets: ["192.168.0.1:9101", "192.168.0.11:9101"]
+
+rule_files:
+    - prometheus_alerts_rules.yml
+
+alerting:
+    alertmanagers:
+        - static_configs:
+              - targets:
+                    - 192.168.0.1:9093