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

@@ -32,12 +32,12 @@ dataset_info:
           0: '0'
           1: '1'
   splits:
-  - name: test
-    num_bytes: 63466
-    num_examples: 758
   - name: train
     num_bytes: 515365
     num_examples: 6136
+  - name: test
+    num_bytes: 63466
+    num_examples: 758
   - name: validation
     num_bytes: 57242
     num_examples: 682