Add two sample implementations

osu.Game/Localisation/Language.cs

@@ -0,0 +1,16 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System.ComponentModel;
+
+namespace osu.Game.Localisation
+{
+    public enum Language
+    {
+        [Description("English")]
+        en,
+
+        [Description("日本語")]
+        ja
+    }
+}