[chore] add datadog extension to opentelemetry integrations menu

Add Datadog Extension to the OpenTelemetry integrations side panel navigation. The documentation was previously added but was missing from the menu configuration, making it inaccessible from the side navigation.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: jackgopack4

config/_default/menus/main.en.yaml

@@ -810,51 +810,56 @@ menu:
       identifier: otel_health_metrics
       parent: otel_integrations
       weight: 803
+    - name: Datadog Extension
+      url: opentelemetry/integrations/datadog_extension/
+      identifier: otel_datadog_extension
+      parent: otel_integrations
+      weight: 804
     - name: Docker Metrics
       url: opentelemetry/integrations/docker_metrics/
       identifier: otel_docker_metrics
       parent: otel_integrations
-      weight: 804
+      weight: 805
     - name: HAProxy Metrics
       url: opentelemetry/integrations/haproxy_metrics/
       identifier: otel_haproxy_metrics
       parent: otel_integrations
-      weight: 805
+      weight: 806
     - name: Host Metrics
       url: opentelemetry/integrations/host_metrics/
       identifier: otel_host_metrics
       parent: otel_integrations
-      weight: 806
+      weight: 807
     - name: IIS Metrics
       url: opentelemetry/integrations/iis_metrics/
       identifier: otel_iis_metrics
       parent: otel_integrations
-      weight: 807
+      weight: 808
     - name: Kafka Metrics
       url: opentelemetry/integrations/kafka_metrics/
       identifier: otel_kafka_metrics
       parent: otel_integrations
-      weight: 808
+      weight: 809
     - name: MySQL Metrics
       url: opentelemetry/integrations/mysql_metrics/
       identifier: otel_mysql_metrics
       parent: otel_integrations
-      weight: 809
+      weight: 810
     - name: NGINX Metrics
       url: opentelemetry/integrations/nginx_metrics/
       identifier: otel_nginx_metrics
       parent: otel_integrations
-      weight: 810
+      weight: 811
     - name: Runtime Metrics
       url: opentelemetry/integrations/runtime_metrics/
       identifier: otel_runtime_metrics
       parent: otel_integrations
-      weight: 811
+      weight: 812
     - name: Trace Metrics
       url: opentelemetry/integrations/trace_metrics/
       identifier: otel_trace_metrics
       parent: otel_integrations
-      weight: 812
+      weight: 813
     - name: Troubleshooting
       url: opentelemetry/troubleshooting/
       identifier: otel_troubleshooting