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

@@ -148,15 +148,15 @@ dataset_info:
   - name: id
     dtype: string
   splits:
-  - name: test
-    num_bytes: 524455
-    num_examples: 5427
   - name: train
     num_bytes: 4224198
     num_examples: 43410
   - name: validation
     num_bytes: 527131
     num_examples: 5426
+  - name: test
+    num_bytes: 524455
+    num_examples: 5427
   download_size: 4394818
   dataset_size: 5275784
 ---