transformers pytorch tf jax tflite rust coreml gpt2 text-generation exbert en dataset:openwebtext arxiv:1910.01108 arxiv:2201.08542 arxiv:2203.12574 arxiv:1910.09700 arxiv:1503.02531 license:apache-2.0 model-index co2_eq_emissions autotrain_compatible text-generation-inference endpoints_compatible region:us