DOCS-17460 Add deprecation warning for map reduce

Author: ianf-mongodb

source/includes/fact-use-aggregation-not-map-reduce.rst

@@ -1,3 +1,6 @@
+As of MongoDB 5.0 the :doc:`map-reduce</core/map-reduce>`
+operation is deprecated.
+
 An :doc:`aggregation pipeline </core/aggregation-pipeline>` provides
 better performance and usability than a :doc:`map-reduce
 </core/map-reduce>` operation.

source/release-notes/5.0.txt

@@ -86,6 +86,16 @@ measurements over a period of time. Compared to normal collections,
 storing time series data in time series collections improves query
 efficiency and reduces disk usage for your data and indexes.
 
+Deprecate Map Reduce Operation
+------------------------------
+
+Starting in version 5.0, MongoDB deprecates the
+:doc:`map-reduce</core/map-reduce>` operation.
+
+For examples of aggregation pipeline alternatives to map-reduce
+operations, see :doc:`/reference/map-reduce-to-aggregation-pipeline` and
+:doc:`/tutorial/map-reduce-examples`.
+
 Aggregation
 -----------