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

@@ -39,15 +39,15 @@ dataset_info:
   - name: bbc_url_id
     dtype: string
   splits:
-  - name: test
-    num_bytes: 55652
-    num_examples: 379
   - name: train
     num_bytes: 197117
     num_examples: 1340
   - name: validation
     num_bytes: 27771
     num_examples: 189
+  - name: test
+    num_bytes: 55652
+    num_examples: 379
   download_size: 265480
   dataset_size: 280540
 ---