Updating dotnet-svcutil guide for version 2.0. (dotnet#10506)

* Updating dotnet-svcutil guide for version 2.0.

* Adding tabs with instructions for previous version, and changing the example from a console app to a web app.

* Fixing incorrect numbering.

* Apply suggestions from code review

Co-Authored-By: dasetser <dasetser@microsoft.com>

* Addressing review feedback.

Author: dasetser

docs/core/additional-tools/dotnet-svcutil-guide.md

@@ -2,7 +2,7 @@
 title: WCF svcutil tool overview
 description: An overview of the Microsoft WCF dotnet-svcutil tool that adds functionality for .NET Core and ASP.NET Core projects, similar to the WCF svcutil tool for .NET Framework projects.
 author: mlacouture
-ms.date: 08/20/2018
+ms.date: 02/22/2019
 ms.custom: "seodec18"
 ---
 # WCF dotnet-svcutil tool for .NET Core
@@ -18,12 +18,19 @@ The **dotnet-svcutil** tool is an alternative option to the [**WCF Web Service R
 
 ## Prerequisites
 
-* [.NET Core SDK](https://dotnet.microsoft.com/download) v1.0.4 or later versions
+# [dotnet-svcutil 2.x](#tab/dotnetsvcutil2x)
+* [.NET Core 2.1 SDK](https://dotnet.microsoft.com/download) or later versions
 * Your favorite code editor
 
+# [dotnet-svcutil 1.x](#tab/dotnetsvcutil1x)
+* [.NET Core 1.0.4 SDK](https://dotnet.microsoft.com/download) or later versions
+* Your favorite code editor
+
+---
+
 ## Getting started
 
-The following example walks you through the steps required to add a web service reference to a .NET Core console project and invoke the service. You will create a .NET Core console application named _HelloSvcutil_ and will add a reference to a web service that implements the following contract:
+The following example walks you through the steps required to add a web service reference to a .NET Core web project and invoke the service. You'll create a .NET Core web application named _HelloSvcutil_ and add a reference to a web service that implements the following contract:
 
 ```csharp
 [ServiceContract]
@@ -34,7 +41,7 @@ public interface ISayHello
 }
 ```
 
-For this example, the web service will be assumed to be hosted at the following address: `http://contoso.com/SayHello.svc`
+For this example, let's assume the web service will be hosted at the following address: `http://contoso.com/SayHello.svc`
 
 From a Windows, macOS, or Linux command window perform the following steps:
 
@@ -45,73 +52,116 @@ mkdir HelloSvcutil
 cd HelloSvcutil
 ```
 
-2. Create a new C# console project in that directory using the [`dotnet new`](../tools/dotnet-new.md) command as follows:
+2. Create a new C# web project in that directory using the [`dotnet new`](../tools/dotnet-new.md) command as follows:
+
+```console
+dotnet new web
+```
 
+3. Install the [`dotnet-svcutil` NuGet package](https://nuget.org/packages/dotnet-svcutil) as a CLI tool:
+# [dotnet-svcutil 2.x](#tab/dotnetsvcutil2x)
 ```console
-dotnet new console
+dotnet tool install --global dotnet-svcutil
 ```
 
-3. Open the `HelloSvcutil.csproj` project file in your editor, edit the `Project` element, and add the [`dotnet-svcutil` NuGet package](https://nuget.org/packages/dotnet-svcutil) as a CLI tool reference, using the following code:
+# [dotnet-svcutil 1.x](#tab/dotnetsvcutil1x)
+Open the `HelloSvcutil.csproj` project file in your editor, edit the `Project` element, and add the [`dotnet-svcutil` NuGet package](https://nuget.org/packages/dotnet-svcutil) as a CLI tool reference, using the following code:
 
 ```xml
 <ItemGroup>
   <DotNetCliToolReference Include="dotnet-svcutil" Version="1.0.*" />
 </ItemGroup>
 ```
 
-4. Restore the _dotnet-svcutil_ package using the [`dotnet restore`](../tools/dotnet-restore.md) command as follows:
+Then restore the _dotnet-svcutil_ package using the [`dotnet restore`](../tools/dotnet-restore.md) command as follows:
 
 ```console
 dotnet restore
 ```
 
-5. Run _dotnet_ with the _svcutil_ command to generate the web service reference file as follows:
+---
+
+4. Run the _dotnet-svcutil_ command to generate the web service reference file as follows:
+# [dotnet-svcutil 2.x](#tab/dotnetsvcutil2x)
+```console
+dotnet-svcutil http://contoso.com/SayHello.svc
+```
 
+# [dotnet-svcutil 1.x](#tab/dotnetsvcutil1x)
 ```console
 dotnet svcutil http://contoso.com/SayHello.svc
 ```
-The generated file is saved as _HelloSvcutil/ServiceReference1/Reference.cs_. The _dotnet_svcutil_ tool also adds to the project the appropriate WCF packages required by the proxy code as package references.
+---
+
+The generated file is saved as _HelloSvcutil/ServiceReference/Reference.cs_. The _dotnet-svcutil_ tool also adds to the project the appropriate WCF packages required by the proxy code as package references.
 
-6. Restore the WCF packages using the [`dotnet restore`](../tools/dotnet-restore.md) command as follows:
+## Using the Service Reference
+
+1. Restore the WCF packages using the [`dotnet restore`](../tools/dotnet-restore.md) command as follows:
 
 ```console
 dotnet restore
 ```
 
-7. Open the `Program.cs` file in your editor, edit the `Main()` method, and replace the auto-generated code with the following code to invoke the web service:
+2. Find the name of the client class and operation you want to use. `Reference.cs` will contain a class that inherits from `System.ServiceModel.ClientBase`, with methods that can be used to call operations on the service. In this example, you want to call the _SayHello_ service's _Hello_ operation. `ServiceReference.SayHelloClient` is the name of the client class, and has a method called `HelloAsync` that can be used to call the operation.
+
+3. Open the `Startup.cs` file in your editor, and add a using statement for the service reference namespace at the top:
 
 ```csharp
-static void Main(string[] args)
+using ServiceReference;
+```
+
+ 4. Edit the `Configure` method to invoke the web service. You do this by creating an instance of the class that inherits from `ClientBase` and calling the method on the client object:
+
+```csharp
+public void Configure(IApplicationBuilder app, IHostingEnvironment env)
 {
-    var client = new SayHelloClient();
-    Console.WriteLine(client.HelloAsync("dotnet-svcutil").Result);
+    if (env.IsDevelopment())
+    {
+        app.UseDeveloperExceptionPage();
+    }
+
+    app.Run(async (context) =>
+    {
+        var client = new SayHelloClient();
+        var response = await client.HelloAsync();
+        await context.Response.WriteAsync(response);
+    });
 }
+
 ```
 
-8. Run the application using the [`dotnet run`](../tools/dotnet-run.md) command as follows:
+5. Run the application using the [`dotnet run`](../tools/dotnet-run.md) command as follows:
 
 ```console
 dotnet run
 ```
+
+6. Navigate to the URL listed in the console (for example, `http://localhost:5000`) in your web browser.
+
 You should see the following output:
 "Hello dotnet-svcutil!"
 
 For a detailed description of the `dotnet-svcutil` tool parameters, invoke the tool passing the help parameter as follows:
+# [dotnet-svcutil 2.x](#tab/dotnetsvcutil2x)
+```console
+dotnet-svcutil --help
+```
 
+# [dotnet-svcutil 1.x](#tab/dotnetsvcutil1x)
 ```console
 dotnet svcutil --help
 ```
+---
 
-## Next steps
-
-### Feedback & questions
+## Feedback & questions
 
 If you have any questions or feedback, [open an issue on GitHub](https://github.com/dotnet/wcf/issues/new). You can also review any existing questions or issues [at the WCF repo on GitHub](https://github.com/dotnet/wcf/issues?utf8=%E2%9C%93&q=is:issue%20label:tooling).
 
-### Release notes
+## Release notes
 
 * Refer to the [Release notes](https://github.com/dotnet/wcf/blob/master/release-notes/dotnet-svcutil-notes.md) for updated release information, including known issues.
 
-### Information
+## Information
 
 * [dotnet-svcutil NuGet Package](https://nuget.org/packages/dotnet-svcutil)