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

@@ -76,12 +76,12 @@ dataset_info:
           1: neutral
           2: contradiction
   splits:
-  - name: test
-    num_bytes: 1047437
-    num_examples: 5010
   - name: validation
     num_bytes: 518830
     num_examples: 2490
+  - name: test
+    num_bytes: 1047437
+    num_examples: 5010
   download_size: 42113232
   dataset_size: 1566267
 ---