Fix the sample code

README.md

@@ -62,16 +62,10 @@ dataset_info:
 To use for e.g. character modelling:
 
 ```
-d = datasets.load_dataset(name='tiny_shakespeare')['train']
-d = d.map(lambda x: datasets.Value('strings').unicode_split(x['text'], 'UTF-8'))
-# train split includes vocabulary for other splits
-vocabulary = sorted(set(next(iter(d)).numpy()))
-d = d.map(lambda x: {'cur_char': x[:-1], 'next_char': x[1:]})
-d = d.unbatch()
-seq_len = 100
-batch_size = 2
-d = d.batch(seq_len)
-d = d.batch(batch_size)
+d = datasets.load_dataset('tiny_shakespeare', split='train')
+d = d.map(lambda x: {'tokens': list(x['text'])})
+vocabulary = set(d['tokens'][0])
+print(d['tokens'])
 ```
 
 ### Supported Tasks and Leaderboards