docs: add a tutorial on how to write a new health monitor

docs/README.md

@@ -1,3 +1,3 @@
 # NVSentinel Documentation
 
 Welcome! This documentation will help you understand, configure, and operate NVSentinel - an intelligent monitoring and self-healing system for GPU-enabled Kubernetes clusters.
@@ -20,6 +20,12 @@
 **For SREs and monitoring teams** (10 min reference)  
 Complete catalog of all Prometheus metrics exposed by NVSentinel components. Use this to build dashboards and alerts.
 
+### [tutorials/](./tutorials/)
+**Step-by-step developer guides**  
+Hands-on walkthroughs for extending NVSentinel. Start with
+[Writing a New Health Monitor](./tutorials/writing-a-health-monitor.md) to build, deploy,
+and verify a custom fault detector end-to-end (no GPU required).
+
 ### [configuration/](./configuration/)
 **Component configuration guides**  
 Detailed setup instructions for each NVSentinel component. Read these when you need to configure specific monitors, connectors, or remediation modules.

docs/index.yml

@@ -14,6 +14,11 @@ navigation:
       - page: Integrations
         path: INTEGRATIONS.md
 
+  - section: Tutorials
+    contents:
+      - page: Writing a Health Monitor
+        path: tutorials/writing-a-health-monitor.md
+
   - section: Architecture
     contents:
       - page: Data Flow