Adding tabs

Author: SnehaGunda

articles/cosmos-db/how-to-define-unique-keys.md

@@ -34,7 +34,9 @@ This article presents the different ways to define [unique keys](unique-keys.md)
 
 To create a container with unique keys see, [Create an Azure Cosmos container with unique key and TTL](manage-with-powershell.md#create-container-unique-key-ttl)
 
-## Use the .NET SDK V2
+## Use the .NET SDK
+
+# [.NET SDK V2](#tab/dotnetv2)
 
 When creating a new container using the [.NET SDK v2](https://www.nuget.org/packages/Microsoft.Azure.DocumentDB/), a `UniqueKeyPolicy` object can be used to define unique key constraints.
 
@@ -54,7 +56,7 @@ client.CreateDocumentCollectionAsync(UriFactory.CreateDatabaseUri("database"), n
 });
 ```
 
-## Use the .NET SDK V3
+# [.NET SDK V3](#tab/dotnetv3)
 
 When creating a new container using the [.NET SDK v3](https://www.nuget.org/packages/Microsoft.Azure.Cosmos/), use the SDK's fluent API to declare unique keys in a concise and readable way.
 
@@ -70,6 +72,7 @@ await client.GetDatabase("database").DefineContainer(name: "container", partitio
     .Attach()
     .CreateIfNotExistsAsync();
 ```
+---
 
 ## Use the Java SDK