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

@@ -45,15 +45,15 @@ dataset_info:
             8: '8'
             9: '9'
   splits:
-  - name: extra
-    num_bytes: 1868720340
-    num_examples: 202353
-  - name: test
-    num_bytes: 271503052
-    num_examples: 13068
   - name: train
     num_bytes: 390404309
     num_examples: 33402
+  - name: test
+    num_bytes: 271503052
+    num_examples: 13068
+  - name: extra
+    num_bytes: 1868720340
+    num_examples: 202353
   download_size: 2636187279
   dataset_size: 2530627701
 - config_name: cropped_digits
@@ -75,15 +75,15 @@ dataset_info:
           8: '8'
           9: '9'
   splits:
-  - name: extra
-    num_bytes: 967853504
-    num_examples: 531131
-  - name: test
-    num_bytes: 44464040
-    num_examples: 26032
   - name: train
     num_bytes: 128364360
     num_examples: 73257
+  - name: test
+    num_bytes: 44464040
+    num_examples: 26032
+  - name: extra
+    num_bytes: 967853504
+    num_examples: 531131
   download_size: 1575594780
   dataset_size: 1140681904
 ---