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

@@ -83,15 +83,15 @@ dataset_info:
           2: I-Disease
   config_name: ncbi_disease
   splits:
-  - name: test
-    num_bytes: 422842
-    num_examples: 941
   - name: train
     num_bytes: 2355516
     num_examples: 5433
   - name: validation
     num_bytes: 413900
     num_examples: 924
+  - name: test
+    num_bytes: 422842
+    num_examples: 941
   download_size: 1546492
   dataset_size: 3192258
 ---