Transformers PHP onnx t5 summarization translation en fr ro de multilingual dataset:c4 arxiv:1805.12471 arxiv:1708.00055 arxiv:1704.05426 arxiv:1606.05250 arxiv:1808.09121 arxiv:1810.12885 arxiv:1905.10044 arxiv:1910.09700 license:apache-2.0 region:us