fix spelling error (#23143)

change referrred to referred

docs/source/en/preprocessing.mdx

@@ -41,7 +41,7 @@ The main tool for preprocessing textual data is a [tokenizer](main_classes/token
 
 <Tip>
 
-If you plan on using a pretrained model, it's important to use the associated pretrained tokenizer. This ensures the text is split the same way as the pretraining corpus, and uses the same corresponding tokens-to-index (usually referrred to as the *vocab*) during pretraining.
+If you plan on using a pretrained model, it's important to use the associated pretrained tokenizer. This ensures the text is split the same way as the pretraining corpus, and uses the same corresponding tokens-to-index (usually referred to as the *vocab*) during pretraining.
 
 </Tip>