Update README

Author: mkkellogg

README.md

@@ -5,6 +5,8 @@ Three.js-based implemetation of a renderer for [3D Gaussian Splatting for Real-T
 The 3D scenes are stored in a format similar to point clouds and can be viewed, navigated, and interacted with in real-time. This renderer will work with the `.ply` files generated by the INRIA project, standard `.splat` files, or my own custom `.ksplat` files, which are a trimmed-down and compressed version of the original `.ply` files.
 
 When I started, web-based viewers were already available -- A WebGL-based viewer from [antimatter15](https://github.com/antimatter15/splat) and a WebGPU viewer from [cvlab-epfl](https://github.com/cvlab-epfl/gaussian-splatting-web) -- However no Three.js version existed. I used those versions as a starting point for my initial implementation, but as of now this project contains all my own code.
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+:warning:  As many of you have noticed, this repo is no longer in active development. It was more of a side project and I don't currently have anywhere near enough bandwidth to devote meaningful development time to it. I recommend checking out [Spark](https://github.com/sparkjsdev/spark) as an alternative -- it is very much in active development by the talented folks at [World Labs](https://www.worldlabs.ai/) and the open-source community, and contains a bunch of advanced features and capabilities.
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 ## Highlights