mlc-llm facebook meta pytorch llama llama-3 text-generation conversational en de fr it pt hi es th arxiv:2308.13137 base_model:meta-llama/Llama-3.1-8B-Instruct base_model:quantized:meta-llama/Llama-3.1-8B-Instruct license:llama3.1 4-bit region:us