Update README

Author: devlights

README.md

@@ -1,16 +1,10 @@
 # try-csharp
 This is my TUTORIAL project for csharp. (dotnet core)
 
-![try-csharp - DotNet Version](https://img.shields.io/badge/dotnetcore-3.1-blue.svg)
+![try-csharp - DotNet Version](https://img.shields.io/badge/dotnet-5.0-blue.svg)
 [![CodeFactor](https://www.codefactor.io/repository/github/devlights/try-csharp/badge)](https://www.codefactor.io/repository/github/devlights/try-csharp)
 [![Gitpod Ready-to-Code](https://img.shields.io/badge/Gitpod-Ready--to--Code-blue?logo=gitpod)](https://gitpod.io/#https://github.com/devlights/try-csharp) 
 
-# Editor
-- JetBrains Rider
-- Microsoft VisualStudio
-- Visual Studio Code
-- Gitpod
-
 # Run (IDE)
 + set TryCSharp.Tools.Cui project as 'startup project'
 + run onto IDE