DOC Fix typo in docstring for Pipeline __getitem__ method (scikit-learn#20523)

Co-authored-by: bumblebebee211196 <[email protected]>

Author: bumblebee211196

sklearn/pipeline.py

@@ -218,7 +218,7 @@ def __len__(self):
         return len(self.steps)
 
     def __getitem__(self, ind):
-        """Returns a sub-pipeline or a single esimtator in the pipeline
+        """Returns a sub-pipeline or a single estimator in the pipeline
 
         Indexing with an integer will return an estimator; using a slice
         returns another Pipeline instance which copies a slice of this