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

@@ -18,15 +18,6 @@ task_categories:
 task_ids: []
 paperswithcode_id: acronym-identification
 pretty_name: Acronym Identification Dataset
-train-eval-index:
-- config: default
-  task: token-classification
-  task_id: entity_extraction
-  splits:
-    eval_split: test
-  col_mapping:
-    tokens: tokens
-    labels: tags
 tags:
 - acronym-identification
 dataset_info:
@@ -39,11 +30,11 @@ dataset_info:
     sequence:
       class_label:
         names:
-          0: B-long
-          1: B-short
-          2: I-long
-          3: I-short
-          4: O
+          '0': B-long
+          '1': B-short
+          '2': I-long
+          '3': I-short
+          '4': O
   splits:
   - name: train
     num_bytes: 7792803
@@ -56,6 +47,15 @@ dataset_info:
     num_examples: 1750
   download_size: 8556464
   dataset_size: 9733236
+train-eval-index:
+- config: default
+  task: token-classification
+  task_id: entity_extraction
+  splits:
+    eval_split: test
+  col_mapping:
+    tokens: tokens
+    labels: tags
 ---
 
 # Dataset Card for Acronym Identification Dataset