Update readme.md

readme.md

@@ -245,7 +245,8 @@ There is a vibrant and extensive eco system around three-fiber, full of librarie
 - [`maath`](https://github.com/pmndrs/maath) – a kitchen sink for math helpers
 - [`miniplex`](https://github.com/hmans/miniplex) – ECS (entity management system)
 - [`composer-suite`](https://github.com/hmans/composer-suite) – composing shaders, particles, effects and game mechanics
-- [`koestlich`](https://github.com/coconut-xr/koestlich) – UI component library
+- [`triplex`](https://triplex.dev/) – scene editor for react-three-fiber
+- [`koestlich`](https://github.com/coconut-xr/koestlich) – UI component library for react-three-fiber
 
 # How to contribute