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

@@ -31,12 +31,12 @@ dataset_info:
     dtype: int64
   config_name: laroseda
   splits:
-  - name: test
-    num_bytes: 700834
-    num_examples: 3000
   - name: train
     num_bytes: 2932819
     num_examples: 12000
+  - name: test
+    num_bytes: 700834
+    num_examples: 3000
   download_size: 5257183
   dataset_size: 3633653
 ---
@@ -192,4 +192,4 @@ CC BY-SA 4.0 License
 
 ### Contributions
 
-Thanks to [@MihaelaGaman](https://github.com/MihaelaGaman) for adding this dataset.
+Thanks to [@MihaelaGaman](https://github.com/MihaelaGaman) for adding this dataset.