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
   config_name: species_800
   splits:
-  - name: test
-    num_bytes: 737760
-    num_examples: 1631
   - name: train
     num_bytes: 2579096
     num_examples: 5734
   - name: validation
     num_bytes: 385756
     num_examples: 831
+  - name: test
+    num_bytes: 737760
+    num_examples: 1631
   download_size: 18204624
   dataset_size: 3702612
 ---