Updated readme

README.md

@@ -27,3 +27,10 @@ configs:
   - split: test
     path: data/test-*
 ---
+
+This dataset is a reranking-formatted version of the Natural Questions dataset from the BEIR benchmark.
+
+Original Dataset: Natural Questions from Google Research  
+BEIR Version: BeIR/nq  
+License: CC-BY-SA-3.0 (based on Wikipedia content)  
+Task: Open-domain question answering