Migrate model card from transformers-repo

Read announcement at https://discuss.huggingface.co/t/announcement-all-model-cards-will-be-migrated-to-hf-co-model-repos/2755
Original file history: https://github.com/huggingface/transformers/commits/master/model_cards/google/roberta2roberta_L-24_bbc/README.md

README.md

@@ -0,0 +1,58 @@
+---
+language: en
+license: apache-2.0
+datasets:
+- xsum
+tags:
+- summarization
+---
+
+# Roberta2Roberta_L-24_bbc EncoderDecoder model
+
+The model was introduced in 
+[this paper](https://arxiv.org/abs/1907.12461) by Sascha Rothe, Shashi Narayan, Aliaksei Severyn and first released in [this repository](https://tfhub.dev/google/bertseq2seq/roberta24_bbc/1). 
+
+The model is an encoder-decoder model that was initialized on the `roberta-large` checkpoints for both the encoder 
+and decoder and fine-tuned on extreme summarization on the BBC XSum dataset, which is linked above.
+
+Disclaimer: The model card has been written by the Hugging Face team.
+
+## How to use
+
+You can use this model for extreme summarization, *e.g.*
+
+```python
+from transformers import AutoTokenizer, AutoModelForSeq2SeqLM
+
+tokenizer = AutoTokenizer.from_pretrained("google/roberta2roberta_L-24_bbc")
+model = AutoModelForSeq2SeqLM.from_pretrained("google/roberta2roberta_L-24_bbc")
+
+article = """The problem is affecting people using the older
+versions of the PlayStation 3, called the "Fat"
+model.The problem isn't affecting the newer PS3
+Slim systems that have been on sale since
+September last year.Sony have also said they are
+aiming to have the problem fixed shortly but is
+advising some users to avoid using their console
+for the time being."We hope to resolve this
+problem within the next 24 hours," a statement
+reads. "In the meantime, if you have a model other
+than the new slim PS3, we advise that you do not
+use your PS3 system, as doing so may result in
+errors in some functionality, such as recording
+obtained trophies, and not being able to restore
+certain data."We believe we have identified that
+this problem is being caused by a bug in the clock
+functionality incorporated in the system."The
+PlayStation Network is used by millions of people
+around the world.It allows users to play their
+friends at games like Fifa over the internet and
+also do things like download software or visit
+online stores."""
+
+input_ids = tokenizer(article, return_tensors="pt").input_ids
+output_ids = model.generate(input_ids)[0]
+print(tokenizer.decode(output_ids, skip_special_tokens=True))
+# should output
+# Some Sony PlayStation gamers are being advised to stay away from the network because of a problem with the PlayStation 3 network.
+```