Add credential builder context (#43708)

* Add credential builder context

docs/azure/sdk/authentication/credential-chains.md

@@ -63,7 +63,7 @@ The order in which `DefaultAzureCredential` attempts credentials follows.
 
 In its simplest form, you can use the parameterless version of `DefaultAzureCredential` as follows:
 
-:::code language="csharp" source="../snippets/authentication/credential-chains/Program.cs" id="snippet_Dac" highlight="1":::
+:::code language="csharp" source="../snippets/authentication/credential-chains/Program.cs" id="snippet_Dac" highlight="6":::
 
 > [!TIP]
 > The `UseCredential` method in the preceding code snippet is recommended for use in ASP.NET Core apps. For more information, see [Use the Azure SDK for .NET in ASP.NET Core apps](../aspnetcore-guidance.md#authenticate-using-microsoft-entra-id).
@@ -72,7 +72,7 @@ In its simplest form, you can use the parameterless version of `DefaultAzureCred
 
 To remove a credential from `DefaultAzureCredential`, use the corresponding `Exclude`-prefixed property in [DefaultAzureCredentialOptions](/dotnet/api/azure.identity.defaultazurecredentialoptions?view=azure-dotnet&preserve-view=true#properties). For example:
 
-:::code language="csharp" source="../snippets/authentication/credential-chains/Program.cs" id="snippet_DacExcludes" highlight="4-5":::
+:::code language="csharp" source="../snippets/authentication/credential-chains/Program.cs" id="snippet_DacExcludes" highlight="9-10":::
 
 In the preceding code sample, `EnvironmentCredential` and `WorkloadIdentityCredential` are removed from the credential chain. As a result, the first credential to be attempted is `ManagedIdentityCredential`. The modified chain looks like this:
 
@@ -97,7 +97,7 @@ As more `Exclude`-prefixed properties are set to `true` (credential exclusions a
 
 [ChainedTokenCredential](/dotnet/api/azure.identity.chainedtokencredential?view=azure-dotnet&preserve-view=true) is an empty chain to which you add credentials to suit your app's needs. For example:
 
-:::code language="csharp" source="../snippets/authentication/credential-chains/Program.cs" id="snippet_Ctc":::
+:::code language="csharp" source="../snippets/authentication/credential-chains/Program.cs" id="snippet_Ctc" highlight="6-8" :::
 
 The preceding code sample creates a tailored credential chain comprised of two credentials. The user-assigned managed identity variant of `ManagedIdentityCredential` is attempted first, followed by `VisualStudioCredential`, if necessary. In graphical form, the chain looks like this:
 

docs/azure/sdk/snippets/authentication/credential-chains/Program.cs

@@ -17,31 +17,45 @@
 }, EventLevel.LogAlways);
 #endregion snippet_FilteredLogging
 
+#region snippet_Dac
 builder.Services.AddAzureClients(clientBuilder =>
 {
     clientBuilder.AddBlobServiceClient(
         new Uri("https://<account-name>.blob.core.windows.net"));
-    #region snippet_Dac
+
     DefaultAzureCredential credential = new();
     clientBuilder.UseCredential(credential);
-    #endregion snippet_Dac
+});
+#endregion snippet_Dac
+
+#region snippet_DacExcludes
+builder.Services.AddAzureClients(clientBuilder =>
+{
+    clientBuilder.AddBlobServiceClient(
+        new Uri("https://<account-name>.blob.core.windows.net"));
 
-    #region snippet_DacExcludes
     clientBuilder.UseCredential(new DefaultAzureCredential(
         new DefaultAzureCredentialOptions
         {
             ExcludeEnvironmentCredential = true,
             ExcludeWorkloadIdentityCredential = true,
             ManagedIdentityClientId = userAssignedClientId,
         }));
-    #endregion snippet_DacExcludes
+});
+#endregion snippet_DacExcludes
+
+#region snippet_Ctc
+builder.Services.AddAzureClients(clientBuilder =>
+{
+    clientBuilder.AddBlobServiceClient(
+        new Uri("https://<account-name>.blob.core.windows.net"));
 
-    #region snippet_Ctc
     clientBuilder.UseCredential(new ChainedTokenCredential(
         new ManagedIdentityCredential(clientId: userAssignedClientId),
         new VisualStudioCredential()));
-    #endregion snippet_Ctc
 });
+#endregion snippet_Ctc
+
 
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();