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

@@ -79,12 +79,12 @@ dataset_info:
     - name: related_links
       dtype: string
   splits:
-  - name: test
-    num_bytes: 1466749978
-    num_examples: 43228
   - name: train
     num_bytes: 5303005740
     num_examples: 151295
+  - name: test
+    num_bytes: 1466749978
+    num_examples: 43228
   - name: validation
     num_bytes: 740962715
     num_examples: 21613