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

@@ -108,12 +108,12 @@ dataset_info:
   - name: answer_token_ranges
     dtype: string
   splits:
-  - name: test
-    num_bytes: 19763673
-    num_examples: 5126
   - name: train
     num_bytes: 362031288
     num_examples: 92549
+  - name: test
+    num_bytes: 19763673
+    num_examples: 5126
   - name: validation
     num_bytes: 19862778
     num_examples: 5166