Update README.md

updating the path to: `apple/mistral-coreml`. in:
```bash
huggingface-cli download \
--local-dir models \
--local-dir-use-symlinks False \
apple/mistral-coreml \
--include "StatefulMistral7BInstructInt4.mlpackage/*"
```

README.md

@@ -38,7 +38,7 @@ To download one of the `.mlpackage` folders to the `models` directory:
 huggingface-cli download \
   --local-dir models \
   --local-dir-use-symlinks False \
-  apple/coreml-mistral-7b-instruct-v0.3 \
+  apple/mistral-coreml \
   --include "StatefulMistral7BInstructInt4.mlpackage/*"
 ```