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

@@ -34,15 +34,15 @@ dataset_info:
           2: I-GENE
   config_name: bc2gm_corpus
   splits:
-  - name: test
-    num_bytes: 2454621
-    num_examples: 5001
   - name: train
     num_bytes: 6095172
     num_examples: 12501
   - name: validation
     num_bytes: 1215951
     num_examples: 2501
+  - name: test
+    num_bytes: 2454621
+    num_examples: 5001
   download_size: 4636753
   dataset_size: 9765744
 ---