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

@@ -31,15 +31,15 @@ dataset_info:
   - name: commit_id
     dtype: string
   splits:
-  - name: test
-    num_bytes: 5646752
-    num_examples: 2732
   - name: train
     num_bytes: 45723487
     num_examples: 21854
   - name: validation
     num_bytes: 5582545
     num_examples: 2732
+  - name: test
+    num_bytes: 5646752
+    num_examples: 2732
   download_size: 61685715
   dataset_size: 56952784
 ---