(DOCS-15193): Add v5.0 language features to Stable API (#1127)

* (DOCS-15193): Add v5.0 language features to Stable API

* add clarifying text

* remove extra text

* update release notes

* fix release notes table

* updates per review

* change header wording

* change header wording

Author: jeff-allen-mongo

source/reference/stable-api-changelog.txt

@@ -16,10 +16,10 @@ This page contains a changelog of the Stable API. The Stable API is
 actively being expanded to include new database commands and
 functionality.
 
-The database commands included in the Stable API depend on the MongoDB
-version you are using. This page describes the MongoDB and Stable API
-versions when a database command or specific sub-features of a command
-are available.
+The commands and operators included in the Stable API depend on the
+MongoDB version you are using. This page describes the MongoDB and
+Stable API versions when a database command or specific sub-features of
+a command are available.
 
 Database Commands
 -----------------
@@ -37,7 +37,7 @@ The following table describes:
 
    * - Command
      - Stable API Version
-     - Added to Stable API in MongoDB Version
+     - Added to Stable API in Version
 
    * - :dbcommand:`count`
      - V1
@@ -129,3 +129,59 @@ The following table describes:
    MongoDB does not guarantee that the output of the
    :dbcommand:`explain` command will conform to the same format in
    future API versions.
+
+Aggregation Stages and Operators
+--------------------------------
+
+The following table describes:
+
+- The aggregation stages and operators included in each version of the
+  Stable API.
+
+- The MongoDB version in which the stage or operator was added to the
+  Stable API.
+
+.. list-table::
+   :header-rows: 1
+   :stub-columns: 1
+   :widths: 15 5 10
+
+   * - Stage or Operator
+     - Stable API Version
+     - Added to Stable API in Version
+
+   * - :expression:`$dateAdd`
+     - V1
+     - MongoDB 6.0
+
+   * - :expression:`$dateDiff`
+     - V1
+     - MongoDB 6.0
+
+   * - :expression:`$dateSubtract`
+     - V1
+     - MongoDB 6.0
+
+   * - :expression:`$dateTrunc`
+     - V1
+     - MongoDB 6.0
+
+   * - :expression:`$getField`
+     - V1
+     - MongoDB 6.0
+
+   * - :expression:`$setField`
+     - V1
+     - MongoDB 6.0
+
+   * - :pipeline:`$setWindowFields`
+     - V1
+     - MongoDB 6.0
+
+   * - :expression:`$tsIncrement`
+     - V1
+     - MongoDB 6.0
+
+   * - :expression:`$tsSecond`
+     - V1
+     - MongoDB 6.0

source/release-notes/6.0.txt

@@ -244,8 +244,17 @@ no longer required to shard a collection.
 Stable API
 ----------
 
-Starting in MongoDB 6.0, the following database commands are included in
-the :ref:`Stable API <stable-api>`:
+The following sections describe additions to the :ref:`Stable API
+<stable-api>` introduced in MongoDB 6.0.
+
+To see the full list of database commands available in the Stable API,
+see :ref:`stable-api-changelog`.
+
+Database Commands
+~~~~~~~~~~~~~~~~~
+
+Starting in MongoDB 6.0, the following database commands are supported
+in the Stable API:
 
 .. list-table::
    :header-rows: 1
@@ -261,8 +270,62 @@ the :ref:`Stable API <stable-api>`:
        in MongoDB 5.0.9.)
      - V1
 
-To see the full list of database commands available in the Stable API,
-see :ref:`stable-api-changelog`.
+Aggregation Stages and Operators
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Starting in MongoDB 6.0, the following aggregation stages and operators
+are supported in the Stable API:
+
+.. list-table::
+   :header-rows: 1
+   :stub-columns: 1
+   :widths: 10 20 10
+
+   * - Stage or Operator
+     - Description
+     - Stable API Version
+
+   * - :expression:`$dateAdd`
+     - Increments a :doc:`Date </reference/method/Date>` object by a
+       specified number of time units.
+     - V1
+
+   * - :expression:`$dateDiff`
+     - Returns the difference between two dates. 
+     - V1
+
+   * - :expression:`$dateSubtract`
+     - Decrements a :doc:`Date </reference/method/Date>` object by a
+       specified number of time units.
+     - V1
+
+   * - :expression:`$dateTrunc`
+     - Truncates a date.
+     - V1
+
+   * - :expression:`$getField`
+     - Returns the value of a specified field from a document.
+     - V1
+
+   * - :expression:`$setField`
+     - Adds, updates, or removes a specified field in a document.
+     - V1
+
+   * - :pipeline:`$setWindowFields`
+     - Performs operations on a specified span of documents in a
+       collection, known as a *window*, and returns the results based on
+       the chosen :ref:`window operator
+       <setWindowFields-window-operators>`.
+     - V1
+
+   * - :expression:`$tsIncrement`
+     - .. include:: /includes/tsIncrement-introduction.rst
+     - V1
+
+   * - :expression:`$tsSecond`
+     - .. include:: /includes/tsSecond-introduction.rst
+     - V1
+
 
 Time Series Collections
 -----------------------