Added C# course (#7555)

* Added C# course

* Update free-courses-en.md

courses/free-courses-en.md

@@ -251,6 +251,7 @@
 
 * [C# 101](https://channel9.msdn.com/Series/CSharp-101) - Scott Hanselman, Kendra Havens (Microsoft)
 * [C# Programming All-in-One Tutorial Series (6 HOURS!)](https://www.youtube.com/watch?v=qOruiBrXlAw) - Caleb Curry (YouTube)
+* [C# Programming Language (Console Applications)](https://youtube.com/playlist?list=PLX07l0qxoHFLZftsVKyj3k9kfMca2uaPR) - Learning Never Ends (YouTube)
 * [C# Tutorial - Full Course for Beginners](https://www.youtube.com/watch?v=GhQdlIFylQ8) - Mike Dane (freeCodeCamp)
 * [C# Tutorial For Beginners - Learn C# Basics in 1 Hour](https://www.youtube.com/watch?v=gfkTfcpWqAY) - Moshfegh Hamedani (Programming with Mosh)
 * [Learn how to program: C# and .NET](https://www.learnhowtoprogram.com/c-and-net) - Epicodus Inc.