gguf quantized 2-bit 3-bit 4-bit 5-bit 6-bit 8-bit GGUF text-generation base_model:mlx-community/Llama-3-Groq-8B-Tool-Use-bf16 base_model:quantized:mlx-community/Llama-3-Groq-8B-Tool-Use-bf16 region:us imatrix conversational