add Programmyday form github

AudioPlayerMusterlösung/AudioFile.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace AudioPlayerMusterlösung
+{
+    abstract class AudioFile
+    {
+        private string fileName;
+        public AudioFile(string filename)
+        {
+            this.fileName = filename;
+        }
+        public string GetFileName()
+        {
+            return fileName;
+        }
+        public abstract void Play();
+
+    }
+}