feat: add Prometheus and Grafana configurations and document Alpine Docker setup

monitoring/prometheus/prometheus.yml

@@ -0,0 +1,10 @@
+global:
+  scrape_interval: 15s
+
+scrape_configs:
+  - job_name: "chat"
+    static_configs:
+      - targets: ["chat:3000"]
+  - job_name: "prometheus"
+    static_configs:
+      - targets: ["prometheus:9090"]