Add comprehensive monitoring guides for Grafana dashboards, alerting setup, and application instrumentation

- Created detailed documentation for creating Grafana dashboards, including best practices, essential panels, and dashboard organization.
- Developed a guide for setting up alerting with Prometheus and Alertmanager, covering configuration, alert rules, and notification channels.
- Introduced application instrumentation techniques for Node.js and React, detailing metrics collection, logging, and API monitoring.