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:
 - token-classification
 task_ids:
 - named-entity-recognition
-paperswithcode_id: null
 pretty_name: People's Daily NER
 dataset_info:
   features:
@@ -29,13 +28,13 @@ dataset_info:
     sequence:
       class_label:
         names:
-          0: O
-          1: B-PER
-          2: I-PER
-          3: B-ORG
-          4: I-ORG
-          5: B-LOC
-          6: I-LOC
+          '0': O
+          '1': B-PER
+          '2': I-PER
+          '3': B-ORG
+          '4': I-ORG
+          '5': B-LOC
+          '6': I-LOC
   config_name: peoples_daily_ner
   splits:
   - name: train