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

@@ -151,15 +151,15 @@ dataset_info:
           1: Neutral
           2: Positive
   splits:
-  - name: test_fixed
-    num_bytes: 3881800
-    num_examples: 827
-  - name: test_random
-    num_bytes: 2629500
-    num_examples: 579
   - name: train
     num_bytes: 14595163
     num_examples: 3355
+  - name: test_random
+    num_bytes: 2629500
+    num_examples: 579
+  - name: test_fixed
+    num_bytes: 3881800
+    num_examples: 827
   - name: validation
     num_bytes: 2322922
     num_examples: 578