chore: add minimal API documentation at root context

infrastructure/src/main/java/com/pablotj/portfolio/infrastructure/rest/api/ApiErrorController.java

@@ -1,4 +1,4 @@
-package com.pablotj.portfolio.infrastructure.rest.config;
+package com.pablotj.portfolio.infrastructure.rest.api;
 
 import org.springframework.boot.web.error.ErrorAttributeOptions;
 import org.springframework.boot.web.servlet.error.ErrorAttributes;

infrastructure/src/main/java/com/pablotj/portfolio/infrastructure/rest/api/ApiRootController.java

@@ -0,0 +1,31 @@
+package com.pablotj.portfolio.infrastructure.rest.api;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+import java.util.Map;
+
+@RestController
+@RequestMapping
+public class ApiRootController {
+
+    @GetMapping
+    public ResponseEntity<Map<String, Object>> root() {
+        Map<String, Object> response = Map.of(
+                "api", "Portfolio API",
+                "version", "1.0",
+                "doc", "/v3/api-docs",
+                "swagger", "/swagger-ui",
+                "endpoints", List.of(
+                        Map.of("path", "/v1/projects", "description", "Manage projects"),
+                        Map.of("path", "/v1/experience", "description", "Experience entries"),
+                        Map.of("path", "/v1/about", "description", "About me")
+                )
+        );
+
+        return ResponseEntity.ok(response);
+    }
+}