Add task category

This PR ensures the dataset shows up in the `image-segmentation` task category.

README.md

@@ -4,7 +4,9 @@ configs:
 - config_name: default
   data_files:
   - split: test
-    path: "GroundingSuite-Eval.jsonl"
+    path: GroundingSuite-Eval.jsonl
+task_categories:
+- image-segmentation
 ---
 
 # 🚀 GSEval - A Comprehensive Grounding Evaluation Benchmark