Update README.md

Add dataset information.

README.md

@@ -23,7 +23,7 @@ should probably proofread and complete it, then remove this comment. -->
 
 # bert-finetuned-ner
 
-This model is a fine-tuned version of [bert-base-cased](https://huggingface.co/bert-base-cased) on an unknown dataset.
+This model is a fine-tuned version of [bert-base-cased](https://huggingface.co/bert-base-cased) on the [CoNLL-2003](https://huggingface.co/datasets/conll2003) dataset.
 It achieves the following results on the evaluation set:
 - Loss: 0.0597
 - Precision: 0.9322