Add extension https://github.com/agnotario/depth-by-y

[agnotario]

GitHub repo: https://github.com/agnotario/depth-by-y
Forum post: https://forum.makecode.com/t/extension-depth-by-y-auto-sorting-sprites-by-y-axis/36151/1
Demo: https://arcade.makecode.com/S23990-49413-21084-04977
Description: Automatically sort sprite layers in MakeCode Arcade based on their Y position to simulate depth in top-down or isometric games. MakeCode Arcade currently lacks a built-in method for controlling sprite layering or z-ordering. This extension aims to fill that gap, providing a simple and accessible solution, especially beneficial in educational settings where students benefit from visual clarity with minimal code complexity.