Blazor ebook frontmatter (#27086)

* Update cs5001.md (#27080)

* Update cs5001.md

* Update docs/csharp/misc/cs5001.md

Co-authored-by: David Pine <david.pine@microsoft.com>

* Remove redundant nullable operator (#27023)

* Remove redundant nullable operator

Remove redundant nullable operator for reference type. String is a reference type and always nullable,

* Make undesired error more clear

Co-authored-by: Bill Wagner <wiwagn@microsoft.com>

Co-authored-by: Bill Wagner <wiwagn@microsoft.com>

* update version

* fix typo

Co-authored-by: Machiel visser <16868513+machielvisser@users.noreply.github.com>
Co-authored-by: David Pine <david.pine@microsoft.com>
Co-authored-by: Artur Khutak <rd.artyrchik@gmail.com>
Co-authored-by: Bill Wagner <wiwagn@microsoft.com>

docs/architecture/blazor-for-web-forms-developers/index.md

@@ -4,17 +4,17 @@ description: Learn how to build full-stack web apps with .NET using Blazor and .
 author: danroth27
 ms.author: daroth
 no-loc: [Blazor, WebAssembly]
-ms.date: 02/02/2021
+ms.date: 11/15/2021
 ---
 # Blazor for ASP.NET Web Forms Developers
 
 ![Screenshot that shows the Serverless Apps e-book cover.](./media/index/blazor-for-aspnet-web-forms-developers.png)
 
 > DOWNLOAD available at: <https://aka.ms/blazor-ebook>
 
-**EDITION v1.0**
+**EDITION v6.0** - Updated to .NET 6
 
-Refer [changelog](https://aka.ms/blazor-ebook-changelog) for the book updates and community contributions.
+Refer to [changelog](https://aka.ms/blazor-ebook-changelog) for the book updates and community contributions.
 
 PUBLISHED BY
 
@@ -50,7 +50,7 @@ Authors:
 
 > **[Scott Addie](https://github.com/scottaddie)**, Senior Content Developer, Microsoft Corp.
 
-> **[Steve "ardalis" Smith](https://ardalis.com)**, Software Architect and Trainer, Ardalis Services LLC
+> **[Steve "@ardalis" Smith](https://github.com/ardalis)**, Software Architect and Trainer, NimblePros.com
 
 ## Introduction
 

docs/csharp/misc/cs5001.md

@@ -14,7 +14,7 @@ Program does not contain a static 'Main' method suitable for an entry point
 
 This error occurs when no static `Main` method with a correct signature is found in the code that produces an executable file. It also occurs if the entry point function, `Main`, is defined with the wrong case, such as lower-case `main`. For information about the rules that apply to the `Main` method, see [Main() and Command-Line Arguments](../fundamentals/program-structure/main-command-line.md).
 
-If the `Main` method has an `async` modifier, make sure that the [selected C# language version](../language-reference/configure-language-version.md) is 7.1 or higher.
+If the `Main` method has an `async` modifier, make sure that the [selected C# language version](../language-reference/configure-language-version.md) is 7.1 or higher and to use `Task` or `Task<int>` as the return type.
 
 The `Main` method is only required when compiling an executable file, that is, when the **exe** or **winexe** element of the [**TargetType**](../language-reference/compiler-options/output.md#targettype) compiler option is specified. The following Visual Studio project types specify one of these options by default:
 

docs/csharp/whats-new/csharp-10.md

@@ -119,7 +119,7 @@ int x = 0;
 Prior to C# 10, there were many scenarios where definite assignment and null-state analysis produced warnings that were false positives. These generally involved comparisons to boolean constants, accessing a variable only in the `true` or `false` statements in an `if` statement, and null coalescing expressions. These examples generated warnings in previous versions of C#, but don't in C# 10:
 
 ```csharp
-string? representation;
+string representation = "N/A";
 if ((c != null) && c.GetDependentValue(out object obj)) == true)
 {
    representation = obj.ToString(); // undesired error