Add pipeline tag and link to GitHub repository

This PR updates the model card to:
- Add the `pipeline_tag: text-classification` metadata to ensure the model is properly indexed and discoverable under the text classification task on the Hugging Face Hub.
- Add a link to the official GitHub repository containing the dataset and modeling code.

README.md

@@ -1,16 +1,18 @@
 ---
 base_model: roberta-base
+datasets:
+- teagrjohnson/narrative-llm-annotations
 language: en
+license: odc-by
+pipeline_tag: text-classification
 tags:
 - narrative
 - text-classification
 - pytorch
-license: odc-by
-datasets:
-- teagrjohnson/narrative-llm-annotations
 ---
 
 - **Paper:** [arXiv:2606.19468](https://arxiv.org/abs/2606.19468)
+- **Repository:** [GitHub](https://github.com/johnsont4/narratives_in_pretraining_data_release)
 - **Collection:** [Narratives in LLM Pretraining Data](https://huggingface.co/collections/teagrjohnson/narratives-in-llm-pretraining-data)
 - **Test it out for yourself:** [NarraBERT space](https://huggingface.co/spaces/teagrjohnson/narrabert)