Fixed typo (#18921)

Fixed typo itmes --> items

docs/source/en/preprocessing.mdx

@@ -54,7 +54,7 @@ Then pass your sentence to the tokenizer:
  'attention_mask': [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]}
 ```
 
-The tokenizer returns a dictionary with three important itmes:
+The tokenizer returns a dictionary with three important items:
 
 * [input_ids](glossary#input-ids) are the indices corresponding to each token in the sentence.
 * [attention_mask](glossary#attention-mask) indicates whether a token should be attended to or not.