Update config to enable docfx v3

Author: VSC-Service-Account

.openpublishing.publish.config.json

@@ -157,7 +157,7 @@
       "url": "https://github.com/Azure-Samples/functions-python-pytorch-tutorial",
       "branch": "master",
       "branch_mapping": {}
-    },   
+    },
     {
       "path_to_root": "functions-quickstart-templates",
       "url": "https://github.com/Azure/azure-functions-templates",
@@ -187,7 +187,8 @@
       "path_to_root": "functions-docs-powershell",
       "url": "https://github.com/Azure-Samples/functions-docs-powershell",
       "branch": "master"
-    },     {
+    },
+    {
       "path_to_root": "samples-personalizer",
       "url": "https://github.com/Azure-Samples/cognitive-services-personalizer-samples",
       "branch": "master"
@@ -366,7 +367,7 @@
       "path_to_root": "azure-sdk-for-java-script-event-hubs",
       "url": "https://github.com/Azure/azure-sdk-for-js/",
       "branch": "master"
-    },        
+    },
     {
       "path_to_root": "azure-sdk-for-net-event-hubs",
       "url": "https://github.com/Azure/azure-sdk-for-net/",
@@ -376,7 +377,7 @@
       "path_to_root": "azure-sdk-for-python-event-hubs",
       "url": "https://github.com/Azure/azure-sdk-for-python/",
       "branch": "master"
-    },      
+    },
     {
       "path_to_root": "cosmos-dotnet-getting-started",
       "url": "https://github.com/Azure-Samples/cosmos-dotnet-getting-started",
@@ -510,5 +511,8 @@
     "Pdf": {
       "template_folder": "_themes.pdf"
     }
+  },
+  "docs_build_engine": {
+    "name": "docfx_v3"
   }
 }