transformers pytorch onnx safetensors t5 text2text-generation generated_from_trainer summarization stacked summaries prompt engineering en dataset:stacked-summaries/stacked-samsum-1024 base_model:google/flan-t5-large base_model:finetune:google/flan-t5-large license:apache-2.0 model-index autotrain_compatible text-generation-inference endpoints_compatible region:us