Add Riggy to Animation (#426)

Co-authored-by: Andrei Vitkouski <andrei.vitkouski@clawbuster.com>
Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

README.md

@@ -152,6 +152,7 @@ _Great graphics placeholders and tools to turn that squared game into a picasso
 - :moneybag: [Mixamo](https://www.mixamo.com/#/) - tool for auto auto rigging and animation of 3D humanoid models,
 - :tada: [NixieFX](https://nixiefx.com/) - Free browser-based particle and VFX editor for Three.js and PixiJS web games, with an open-source runtime.
 - :tada: [Pixel Composer](https://github.com/Ttanasart-pt/Pixel-Composer) - Powerful node-based VFX editor for pixel art
+- :moneybag: [Riggy](https://riggyapp.com/) - AI rigs a layered PSD into a Spine 4.2 skeleton with animations from a text description; exports plain skeleton.json and atlas.
 - :moneybag: [Spine](https://esotericsoftware.com/) - Spine is dedicated to 2D animation, providing an efficient workflow both for creating amazing animation and for integrating it into your games.
 - :moneybag: [Spriter Pro](https://brashmonkey.com/download-spriter-pro/) - Modern tool for sprite animation.