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

@@ -38,12 +38,12 @@ dataset_info:
   - name: target
     sequence: string
   splits:
-  - name: test
-    num_bytes: 1073656
-    num_examples: 618
   - name: train
     num_bytes: 2738065
     num_examples: 1992
+  - name: test
+    num_bytes: 1073656
+    num_examples: 618
   - name: validation
     num_bytes: 994876
     num_examples: 619
@@ -68,12 +68,12 @@ dataset_info:
   - name: target
     sequence: string
   splits:
-  - name: test
-    num_bytes: 4822026
-    num_examples: 618
   - name: train
     num_bytes: 14473822
     num_examples: 1992
+  - name: test
+    num_bytes: 4822026
+    num_examples: 618
   - name: validation
     num_bytes: 4476237
     num_examples: 619
@@ -96,12 +96,12 @@ dataset_info:
   - name: target
     sequence: string
   splits:
-  - name: test
-    num_bytes: 20182554
-    num_examples: 618
   - name: train
     num_bytes: 66917363
     num_examples: 1992
+  - name: test
+    num_bytes: 20182554
+    num_examples: 618
   - name: validation
     num_bytes: 18790651
     num_examples: 619