docs : add `catai` to `README.md` (#2967)

README.md

@@ -120,6 +120,7 @@ as the main playground for developing new features for the [ggml](https://github
 
 - [nat/openplayground](https://github.com/nat/openplayground)
 - [oobabooga/text-generation-webui](https://github.com/oobabooga/text-generation-webui)
+- [withcatai/catai](https://github.com/withcatai/catai)
 
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