Move source projects into source directory

source/MonoGame.Extended.Tiled/TiledMapRectangleObject.cs

@@ -0,0 +1,12 @@
+using Microsoft.Xna.Framework;
+
+namespace MonoGame.Extended.Tiled
+{
+    public sealed class TiledMapRectangleObject : TiledMapObject
+    {
+        public TiledMapRectangleObject(int identifier, string name, Size2 size, Vector2 position, float rotation = 0, float opacity = 1, bool isVisible = true, string type = null) 
+            : base(identifier, name, size, position, rotation, opacity, isVisible, type)
+        {
+        }
+    }
+}