Reorder split names

Reorder split names in the YAML metadata to be aligned with the order in the loading script.
See: https://github.com/huggingface/datasets/issues/5258

README.md

@@ -28,12 +28,12 @@ dataset_info:
   - name: answers
     sequence: string
   splits:
-  - name: test
-    num_bytes: 289824
-    num_examples: 2032
   - name: train
     num_bytes: 533736
     num_examples: 3778
+  - name: test
+    num_bytes: 289824
+    num_examples: 2032
   download_size: 1272965
   dataset_size: 823560
 ---