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

@@ -28,22 +28,22 @@ dataset_info:
     dtype:
       class_label:
         names:
-          0: 'False'
-          1: 'True'
+          '0': 'False'
+          '1': 'True'
   - name: bias
     dtype:
       class_label:
         names:
-          0: none
-          1: gender
-          2: others
+          '0': none
+          '1': gender
+          '2': others
   - name: hate
     dtype:
       class_label:
         names:
-          0: hate
-          1: offensive
-          2: none
+          '0': hate
+          '1': offensive
+          '2': none
   splits:
   - name: train
     num_bytes: 983608