Update task category to `question-answering`

This PR updates the `task_categories` metadata to `question-answering`, which more accurately reflects the dataset's intended use for evaluating information retrieval and RAG systems. I have also made the link name for the Arxiv paper more precise by renaming "Arxiv" to "Paper".

README.md

@@ -1,4 +1,9 @@
 ---
+license: cc-by-sa-4.0
+size_categories:
+- 10K<n<100K
+task_categories:
+- question-answering
 dataset_info:
 - config_name: angular
   features:
@@ -121,19 +126,13 @@ configs:
   data_files:
   - split: train
     path: yolo/train-*
-license: cc-by-sa-4.0
-task_categories:
-- sentence-similarity
-size_categories:
-- 10K<n<100K
 ---
 
 # Dataset Card for FreshStack (Corpus)
 
-## Dataset Description
 [Homepage](https://fresh-stack.github.io) | 
 [Repository](https://github.com/fresh-stack/freshstack) |
-[ArXiv](https://arxiv.org/abs/2504.13128)
+[Paper](https://arxiv.org/abs/2504.13128)
 
 FreshStack is a holistic framework to construct challenging IR/RAG evaluation datasets that focuses on search across niche and recent topics.