Remove "cannot (yet) be instantiated with HF" from README

This PR removes the text "cannot (yet) be instantiated with HF" from README because it currently can thanks to this integration:

https://huggingface.co/mistralai/Mixtral-8x7B-v0.1/discussions/3

Related PR in base model:

https://huggingface.co/mistralai/Mixtral-8x7B-v0.1/discussions/7

README.md

@@ -13,7 +13,7 @@ The Mixtral-8x7B Large Language Model (LLM) is a pretrained generative Sparse Mi
 For full details of this model please read our [release blog post](https://mistral.ai/news/mixtral-of-experts/).
 
 ## Warning
-This repo contains weights that are compatible with [vLLM](https://github.com/vllm-project/vllm) serving of the model as well as Hugging Face [transformers](https://github.com/huggingface/transformers) library. It is based on the original Mixtral [torrent release](magnet:?xt=urn:btih:5546272da9065eddeb6fcd7ffddeef5b75be79a7&dn=mixtral-8x7b-32kseqlen&tr=udp%3A%2F%http://2Fopentracker.i2p.rocks%3A6969%2Fannounce&tr=http%3A%2F%http://2Ftracker.openbittorrent.com%3A80%2Fannounce), but the file format and parameter names are different. Please note that model cannot (yet) be instantiated with HF.
+This repo contains weights that are compatible with [vLLM](https://github.com/vllm-project/vllm) serving of the model as well as Hugging Face [transformers](https://github.com/huggingface/transformers) library. It is based on the original Mixtral [torrent release](magnet:?xt=urn:btih:5546272da9065eddeb6fcd7ffddeef5b75be79a7&dn=mixtral-8x7b-32kseqlen&tr=udp%3A%2F%http://2Fopentracker.i2p.rocks%3A6969%2Fannounce&tr=http%3A%2F%http://2Ftracker.openbittorrent.com%3A80%2Fannounce), but the file format and parameter names are different.
 
 ## Instruction format