Merge pull request #1502 from rahulva-msft/patch-1

Update reference-preview.yml

Author: Taojunshen

docs-ref-mapping/reference-preview.yml

@@ -69,6 +69,12 @@
       landingPageType: Service
       children:
       - azure-communication-identity
+    - name: Netowrk Traversal
+      uid: azure.python.sdk.landingPage.services.Communication.NetworkTraversal.pre
+      href: ~/docs-ref-services/preview/communication-networktraversal-readme.md
+      landingPageType: Service
+      children:
+      - azure-communication-network-traversal      
   - name: Container Registry
     uid: azure.python.sdk.landingPage.services.Container.Registry.pre
     href: ~/docs-ref-services/preview/container-registry.md