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

@@ -17,7 +17,6 @@ task_categories:
 - text-classification
 task_ids:
 - topic-classification
-paperswithcode_id: null
 pretty_name: Yoruba Bbc News Topic Classification Dataset (YorubaBbcTopics)
 dataset_info:
   features:
@@ -27,13 +26,13 @@ dataset_info:
     dtype:
       class_label:
         names:
-          0: africa
-          1: entertainment
-          2: health
-          3: nigeria
-          4: politics
-          5: sport
-          6: world
+          '0': africa
+          '1': entertainment
+          '2': health
+          '3': nigeria
+          '4': politics
+          '5': sport
+          '6': world
   - name: date
     dtype: string
   - name: bbc_url_id