update mapping

Author: JiayueHu

docs-ref-mapping/reference.yml

@@ -157,6 +157,11 @@
       uid: azure.nodejs.sdk.landingpage.services.cognitiveservices
       href: ~/docs-ref-services/cognitive-services.md
       items:
+      - name: Anomaly Detector
+        uid: azure.nodejs.sdk.landingPage.services.Cognitive.Services.AnomalyDetector
+        landingPageType: Service
+        children:
+        - '@azure/cognitiveservices-anomalydetector'
       - name: Bing Auto Suggest
         uid: azure.nodejs.sdk.landingPage.services.Cognitive.Services.Bing.AutoSuggest
         landingPageType: Service