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

@@ -30,15 +30,15 @@ dataset_info:
   - name: section_names
     dtype: string
   splits:
-  - name: test
-    num_bytes: 217514961
-    num_examples: 6440
   - name: train
     num_bytes: 7148341992
     num_examples: 203037
   - name: validation
     num_bytes: 217125524
     num_examples: 6436
+  - name: test
+    num_bytes: 217514961
+    num_examples: 6440
   download_size: 4504646347
   dataset_size: 7582982477
 - config_name: pubmed
@@ -50,15 +50,15 @@ dataset_info:
   - name: section_names
     dtype: string
   splits:
-  - name: test
-    num_bytes: 127184448
-    num_examples: 6658
   - name: train
     num_bytes: 2252027383
     num_examples: 119924
   - name: validation
     num_bytes: 127403398
     num_examples: 6633
+  - name: test
+    num_bytes: 127184448
+    num_examples: 6658
   download_size: 4504646347
   dataset_size: 2506615229
 ---