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

@@ -1,15 +1,14 @@
 ---
 annotations_creators:
 - crowdsourced
-language:
-- en
 language_creators:
 - found
+language:
+- en
 license:
 - unknown
 multilinguality:
 - monolingual
-pretty_name: Abductive Reasoning in narrative Text
 size_categories:
 - 100K<n<1M
 source_datasets:
@@ -20,6 +19,7 @@ task_categories:
 task_ids:
 - natural-language-inference
 paperswithcode_id: art-dataset
+pretty_name: Abductive Reasoning in narrative Text
 tags:
 - abductive-natural-language-inference
 dataset_info:
@@ -36,9 +36,9 @@ dataset_info:
     dtype:
       class_label:
         names:
-          0: '0'
-          1: '1'
-          2: '2'
+          '0': '0'
+          '1': '1'
+          '2': '2'
   config_name: anli
   splits:
   - name: validation