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

@@ -104,18 +104,18 @@ dataset_info:
     - name: source
       dtype: string
   splits:
-  - name: test
-    num_bytes: 2203716
-    num_examples: 500
-  - name: test_ood
-    num_bytes: 2249352
-    num_examples: 509
   - name: train
     num_bytes: 41308170
     num_examples: 3988
   - name: validation
     num_bytes: 5495419
     num_examples: 500
+  - name: test
+    num_bytes: 2203716
+    num_examples: 500
+  - name: test_ood
+    num_bytes: 2249352
+    num_examples: 509
   download_size: 14194578
   dataset_size: 51256657
 ---