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

@@ -52,12 +52,12 @@ dataset_info:
   - name: topic_name
     dtype: string
   splits:
-  - name: test
-    num_bytes: 1447829
-    num_examples: 6150
   - name: train
     num_bytes: 131904057
     num_examples: 182822
+  - name: test
+    num_bytes: 1447829
+    num_examples: 6150
   - name: validation
     num_bytes: 2221468
     num_examples: 4183