TOC: az datadog mapping update (Azure#3451)

Author: dbradish-microsoft

src/service_name.json

@@ -99,6 +99,11 @@
     "AzureServiceName": "Azure Databox",
     "URL": "https://docs.microsoft.com/azure/databox/"
   },
+  {
+    "Command": "az datadog",
+    "AzureServiceName": "Microsoft Partner Services",
+    "URL": "unknown"
+  },
   {
     "Command": "az databricks",
     "AzureServiceName": "Azure Databricks",