DOCSP-18637 Enable M0 instance size for QuickStart command (#629) (#637)

Author: kanchana-mongodb

source/quick-start/atlas.txt

@@ -42,7 +42,7 @@ Before you begin, you must complete the following:
 Configure an |service| Cluster
 ------------------------------
 
-Use the :ref:`mongocli-atlas-quickstart` command to create an ``M2`` 
+Use the :ref:`mongocli-atlas-quickstart` command to create an ``M0`` 
 cluster in |service|.
 
 You can run this command in two ways: 
@@ -75,7 +75,7 @@ Click the tab to see the command for your preferred mode.
       - Cluster name: ``getStarted``
       - Service provider: ``AWS``
       - Provider region: ``US_EAST-1``
-      - Cluster tier: ``M2``
+      - Cluster tier: ``M0``
       - Disk size: ``2`` GB
       - MongoDB version: ``5.0``
       - Replica set members: ``3``