Create hello.cs

还是把语言加上吧，方便第三方热榜网站获取到此repo

Test/hello.cs

@@ -0,0 +1,12 @@
+using System;
+// A "Hello World!" program in C#
+namespace HelloWorld
+{
+    class Hello 
+    {
+        static void Main() 
+        {
+            System.Console.WriteLine("Hello World!");
+        }
+    }
+}