feat: modernize application — source, platform artifacts, CI/CD (#3)

docs/api.md

@@ -0,0 +1,25 @@
+# API Reference
+
+## Endpoints
+
+### Health Check
+
+```
+GET /health
+```
+
+**Response:**
+```json
+{"status": "UP", "service": "demo-raj-1"}
+```
+
+### Root
+
+```
+GET /
+```
+
+**Response:**
+```json
+{"service": "demo-raj-1", "description": "Modernized demo-raj-1 service", "version": "1.0.0"}
+```