transformers safetensors llama text-generation facebook meta pytorch llama-2 conversational en arxiv:2307.09288 base_model:meta-llama/Llama-2-7b-chat-hf base_model:finetune:meta-llama/Llama-2-7b-chat-hf license:llama2 autotrain_compatible text-generation-inference 8-bit region:us