(DOCSP-17435) Documents the default quickstart settings for mongocli atlas (#784) (#789)

* (DOCSP-17435) Documents the default quickstart settings for mongocli atlas

* Includes changes from tech review

Author: sarahsimpers

source/quick-start/atlas.txt

@@ -45,16 +45,55 @@ Configure an |service| Cluster
 Use the :ref:`mongocli-atlas-quickstart` command to create an ``M0`` 
 cluster in |service|.
 
-You can run this command in two ways: 
-      
-- Interactive mode - the command prompts you for the cluster settings 
-  and provides default values. 
-- Noninteractive mode - you run the command with the options.
+You can run this command in the following ways: 
+
+- **Default Settings Mode** - the command creates a sample shared
+  cluster with the default settings.
+- **Interactive mode** - the command prompts you for the cluster
+  settings and provides default values. 
+- **Noninteractive mode** - you run the command with the options.
 
 Click the tab to see the command for your preferred mode. 
 
 .. tabs:: 
 
+   .. tab:: Default Settings Mode
+      :tabid: default
+
+      The command creates a sample shared-tier cluster with the 
+      following default settings:
+ 
+      - ClusterName: ``Quickstart-<number>``
+      - Cloud Provider: ``AWS``
+      - Tier: ``M0``
+      - Region: ``US_EAST_1``
+      - Sample Data: ``No``
+      - Database Username: ``Quickstart-<number>``
+      - Database Password: ``abcdef12345``
+      - MongoShell: ``No``
+
+      .. note::
+
+         The password is a random autogenerated value. ``abcdef12345`` 
+         is an example value.
+  
+      .. io-code-block::
+         
+         .. input::
+            :language: sh
+            
+            mongocli atlas quickstart --default --force
+
+         .. output::
+            :language: sh
+
+            We are deploying Quickstart-9876543...
+            Creating your cluster... [Its safe to 'Ctrl + C']
+
+            Loading sample data into your cluster... [Its safe to 'Ctrl + C']
+
+            Now you can connect to your Atlas cluster with: mongosh -u Quickstart-9876543 -p abcdef12345 mongodb+srv://quickstart-9876543.example.mongodb.net
+
    .. tab:: Interactive Mode
       :tabid: interactive