Add pixelfx.io and VfxSmith game VFX resources (#511)

README.md

@@ -84,6 +84,7 @@ _Great graphics placeholders and tools to turn that squared game into a picasso
 - :free: [Minecraft Pixel Art](https://minecraft-pixel-art.com/editor/blueprint) - Browser image-to-Minecraft block blueprints with material lists, PNG plans and Java structure NBT export; no account required.
 - :free: [OpenGameArt](https://opengameart.org/) - a media repository intended for use with free software game projects.
 - :moneybag: [Oryx Design Lab](https://oryxdesignlab.com/) - Cheap high quality royalty free sprites
+- :free: [pixelfx.io](https://pixelfx.io/) - Free animated pixel art effects for games, with browser previews, recoloring, and transparent PNG sprite sheet and animation JSON downloads; MIT-licensed library assets.
 - :free: [Pixelicious](https://www.pixelicious.xyz/) - Image-to-Pixel Art converter.
 - :money_with_wings: [PlainTextures](https://www.plaintextures.com/) - Free high resolution textures, brushes and photos
 - :free: [Poly Pizza](https://poly.pizza) - 6000+ free low poly models
@@ -165,6 +166,7 @@ _Great graphics placeholders and tools to turn that squared game into a picasso
 - :money_with_wings: [SlotVFX](https://slotvfx.com/) - Desktop editor for particles and game VFX with Spine support. Free to use; exports for Pixi, Phaser, Cocos Creator and WebGL2 need a paid plan.
 - :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.
+- :money_with_wings: [VfxSmith](https://vfxsmith.com/) - AI pixel art VFX generator for games with chat refinement, editable effect components, and sprite sheet, JSON, GIF, PNG sequence and Godot 4 exports; free library and editing, paid AI generation after initial credits.
 
 #### Vector/Image Editor