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

@@ -13,15 +13,15 @@ dataset_info:
     dtype: string
   config_name: en
   splits:
-  - name: test
-    num_bytes: 522219464
-    num_examples: 162274
   - name: train
     num_bytes: 9423623904
     num_examples: 2926536
   - name: validation
     num_bytes: 527383016
     num_examples: 163597
+  - name: test
+    num_bytes: 522219464
+    num_examples: 162274
   download_size: 0
   dataset_size: 10473226384
 ---