Librarian Bot: Add base_model information to model

Add verifyToken field to verify evaluation results are produced by Hugging Face's automatic model evaluator (#3)

Update README.md

Add evaluation results on the default config and validation split of xsum (#2)

Add evaluation results on the default config and test split of xsum (#1)

Update README.md

Update README.md

Update README.md

Update README.md

update model card README.md

update model card README.md