fix(docker-compose, prometheus): remove unnecessary comments and improve clarity

docker-compose.metrics.yml

@@ -39,7 +39,7 @@ services:
       - "9090:9090"
 
   grafana:
-    image: grafana/grafana:latest
+    image: grafana/grafana:12.2.0
     container_name: newt-metrics-grafana
     restart: unless-stopped
     environment:
@@ -52,4 +52,4 @@ services:
     volumes:
       - ./examples/grafana/provisioning/datasources:/etc/grafana/provisioning/datasources:ro
       - ./examples/grafana/provisioning/dashboards:/etc/grafana/provisioning/dashboards:ro
-      - ./examples/grafana/dashboards:/var/lib/grafana/dashboards:ro
+      - ./examples/grafana/dashboards:/var/lib/grafana/dashboards:ro

examples/prometheus.with-collector.yml

@@ -14,4 +14,3 @@ scrape_configs:
       # - action: keep
       #   source_labels: [site_id]
       #   regex: '(site-a|site-b)'
-