update chapter 1 readme

it's a Razor web app, not MVC

Author: christiannagel

1_CS/HelloWorld/Readme.md

@@ -5,12 +5,12 @@
 This chapter contains the following code samples:
 
 * HelloWorld (.NET Core Console App)
-* WebApp (Tool-generated ASP.NET Core MVC Web App)
+* WebApp (Tool-generated ASP.NET Core Web App)
 * SelfContainedHelloWorld (Console App configured for self-contained deployment)
 * TrimmedHelloWorld
 
 For code comments and issues please check [Professional C#'s GitHub Repository](https://github.com/ProfessionalCSharp/ProfessionalCSharp2021)
 
 Please check my blog [csharp.christiannagel.com](https://csharp.christiannagel.com "csharp.christiannagel.com") for additional information for topics covered in the book.
 
-Thank you!
+Thank you!