DOCS-942 add show databases as alias to show dbs (delay merge to 2.3.1)

source/reference/mongo-shell-reference.txt

@@ -70,6 +70,12 @@ displays some common help methods and commands:
      - Show help on collection methods. The ``<collection>`` can be the
        name of an existing collection or a non-existing collection.
 
+   .. versionadded:: 2.3.1
+
+   * - ``show databases``
+
+     - Print a list of all databases on the server.
+
    * - ``show dbs``
 
      - Print a list of all databases on the server.

source/tutorial/access-mongo-shell-help.txt

@@ -43,8 +43,10 @@ To see the list of help, in the :program:`mongo` shell, type ``help``:
 Database Help
 -------------
 
+.. versionchanged:: 2.3.1
+
 - To see the list of databases on the server, use the ``show dbs``
-  command:
+  or ``show databases`` command:
 
   .. code-block:: javascript
 

source/tutorial/getting-started.txt

@@ -90,6 +90,13 @@ you insert data into that database. The
 :ref:`getting-started-create-documents` section describes the process
 for inserting data.
 
+.. versionadded:: 2.3.1
+
+   .. note::
+
+      :command:`show databases` will also return a list of databases.
+
+
 Display ``mongo`` Help
 ~~~~~~~~~~~~~~~~~~~~~~