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

@@ -85,12 +85,12 @@ dataset_info:
           5: B_DT
           6: B_PS
   splits:
-  - name: test
-    num_bytes: 476850
-    num_examples: 366
   - name: train
     num_bytes: 3948938
     num_examples: 2928
+  - name: test
+    num_bytes: 476850
+    num_examples: 366
   - name: validation
     num_bytes: 486178
     num_examples: 366