peft tensorboard safetensors llama alignment-handbook generated_from_trainer trl dpo dataset:HuggingFaceH4/ultrafeedback_binarized base_model:meta-llama/Llama-2-7b-chat-hf base_model:adapter:meta-llama/Llama-2-7b-chat-hf 4-bit bitsandbytes region:us