transformers safetensors llama text-generation alignment-handbook conversational dataset:openbmb/UltraFeedback arxiv:2406.11827 base_model:meta-llama/Meta-Llama-3-8B-Instruct base_model:finetune:meta-llama/Meta-Llama-3-8B-Instruct autotrain_compatible text-generation-inference endpoints_compatible region:us