Move solution and projects to src

src/Ryujinx.Input/StickInputId.cs

@@ -0,0 +1,14 @@
+namespace Ryujinx.Input
+{
+    /// <summary>
+    /// Represent a joystick from a gamepad.
+    /// </summary>
+    public enum StickInputId : byte
+    {
+        Unbound,
+        Left,
+        Right,
+
+        Count
+    }
+}