transformers gguf mergekit merge llama-cpp gguf-my-repo base_model:HuggingFaceH4/zephyr-7b-beta base_model:merge:HuggingFaceH4/zephyr-7b-beta base_model:mistralai/Mistral-7B-Instruct-v0.3 base_model:merge:mistralai/Mistral-7B-Instruct-v0.3 endpoints_compatible region:us conversational