docs: rewrite README with structured overview and quick start guide

Replaces the minimal project description with a comprehensive README
including a component overview table, quick start instructions, common
Ansible operations, and links to detailed documentation. Aligns with
Red Panda Approval™ standards.

ansible/grafana_mcp/docker-compose.yml.j2

@@ -0,0 +1,18 @@
+services:
+  grafana-mcp:
+    image: mcp/grafana:latest
+    pull_policy: always
+    container_name: grafana-mcp
+    restart: unless-stopped
+    ports:
+      - "{{grafana_mcp_port}}:8000"
+    environment:
+      - GRAFANA_URL=http://{{grafana_mcp_grafana_host}}:{{grafana_mcp_grafana_port}}
+      - GRAFANA_SERVICE_ACCOUNT_TOKEN={{grafana_service_account_token}}
+    command: ["--transport", "streamable-http", "--address", "0.0.0.0:8000", "--tls-skip-verify"]
+    logging:
+      driver: syslog
+      options:
+        syslog-address: "tcp://127.0.0.1:{{grafana_mcp_syslog_port}}"
+        syslog-format: "{{syslog_format}}"
+        tag: "grafana-mcp"