DOCS-16612 Add minN to Agg Operators (#6106) (#6174)

* DOCS-16612 Add  to agg operators

* *

* *

* *

Author: ianf-mongodb

source/includes/extracts-agg-operators.yaml

@@ -1138,6 +1138,18 @@ content: |
 
              Available in the :pipeline:`$setWindowFields` stage.
 
+      * - :group:`$minN`
+
+        - Returns an aggregation of the ``n`` minimum valued elements 
+          in a group. 
+          Distinct from the :expression:`$minN` array operator.
+
+          .. versionadded:: 5.2
+
+          Available in :pipeline:`$group`, 
+          :pipeline:`$setWindowFields`
+          and as an :ref:`expression <aggregation-expressions>`.
+
       * - :group:`$push`
 
         - Returns an array of expression values for documents in each