Improve model card: metadata & paper link

This PR addresses several improvements for the model card:

- Corrects the `library_name` metadata from `pytorch` to `transformers` based on the provided usage example and model architecture in `config.json`. This ensures the automated "how to use" widget on the model page functions correctly.
- Adds the `datasets` metadata `uzw/PlainFact`, as the GitHub README for the `PlainQAFact` framework explicitly links to this dataset on the Hugging Face Hub, indicating its strong association with the model.
- Updates the introductory sentence in the model card to accurately link to the [PlainQAFact: Retrieval-augmented Factual Consistency Evaluation Metric for Biomedical Plain Language Summarization](https://huggingface.co/papers/2503.08890) paper and the [GitHub repository](https://github.com/zhiwenyou103/PlainQAFact) for better discoverability.
- Adds a top-level model card title `# uzw/bart-large-question-generation` for better structure.
- Removes the redundant GitHub link at the end of the model card, as it is now included in the introduction.

README.md

@@ -1,17 +1,20 @@
 ---
-license: apache-2.0
 base_model:
 - facebook/bart-large
 language:
 - en
-library_name: pytorch
+library_name: transformers
+license: apache-2.0
 pipeline_tag: text-generation
 tags:
 - question-generation
+datasets:
+- uzw/PlainFact
 ---
 
-> This Question Generation model is a part of the [PlainQAFact](https://github.com/zhiwenyou103/PlainQAFact) factuality evaluation framework. 
+# uzw/bart-large-question-generation
 
+This Question Generation model is part of the [PlainQAFact: Retrieval-augmented Factual Consistency Evaluation Metric for Biomedical Plain Language Summarization](https://huggingface.co/papers/2503.08890) factuality evaluation framework. For more details, refer to the [paper](https://huggingface.co/papers/2503.08890) and the [GitHub repository](https://github.com/zhiwenyou103/PlainQAFact).
 
 ## Generating Questions Given Context and Answers
 
@@ -72,6 +75,4 @@ If you use this QG model in your research, please cite with the following BibTex
       primaryClass={cs.CL},
       url={https://arxiv.org/abs/2503.08890}, 
 }
-```
-
-> Code: https://github.com/zhiwenyou103/PlainQAFact
+```