Add NixieFX to Graphics Animation (#398)

README.md

@@ -135,6 +135,7 @@ _Great graphics placeholders and tools to turn that squared game into a picasso
 - :free: [GameAsset.net](https://gameasset.net/) - 10,000+ free CC0 character animations, previewable in 3D with GLB download.
 - 🆓 [GraphicsDale](https://graphicsgale.com/us/) - Powerful tool for spriting and pixel art.
 - :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: [Spine](http://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.