DOCSP-33122 fix ref (#5320) (#5342)

Author: jocelyn-mendez1

source/tutorial/perform-incremental-map-reduce.txt

@@ -202,8 +202,8 @@ The operation returns the following documents:
 Aggregation Alternative
 -----------------------
 
-As an alternative to map-reduce, you can use an :doc:`aggregation
-pipeline </core/aggregation-pipeline>` that combines :pipeline:`$group`
+As an alternative to map-reduce, you can use an :ref:`aggregation
+pipeline <aggregation-pipeline>` that combines :pipeline:`$group`
 and :pipeline:`$merge` stages to achieve the same result in a more
 flexible operation.