Replace YAML keys from int to str

Replace YAML metadata integer keys with strings, as the Hub does not support integers.
See: https://github.com/huggingface/datasets/issues/5275

README.md

@@ -36,10 +36,10 @@ dataset_info:
     dtype:
       class_label:
         names:
-          0: SUPPORTS
-          1: REFUTES
-          2: NOT_ENOUGH_INFO
-          3: DISPUTED
+          '0': SUPPORTS
+          '1': REFUTES
+          '2': NOT_ENOUGH_INFO
+          '3': DISPUTED
   - name: evidences
     list:
     - name: evidence_id
@@ -48,9 +48,9 @@ dataset_info:
       dtype:
         class_label:
           names:
-            0: SUPPORTS
-            1: REFUTES
-            2: NOT_ENOUGH_INFO
+            '0': SUPPORTS
+            '1': REFUTES
+            '2': NOT_ENOUGH_INFO
     - name: article
       dtype: string
     - name: evidence