(DOCSP-26031) Makes two small updates to quickstart tutorial (#73)

Author: sarahsimpers

source/atlas-cli-quickstart.txt

@@ -63,7 +63,7 @@ Click the tab to see the command for your preferred mode.
 
       - Cluster name: ``Quickstart-<number>``
       - Service provider: ``AWS``
-      - Provider region: ``US_EAST-1``
+      - Provider region: ``US_EAST_1``
       - Cluster tier: ``M0``
       - Disk size: ``0.5`` GB
       - Database Username: ``Quickstart-<number>``
@@ -72,6 +72,11 @@ Click the tab to see the command for your preferred mode.
       - Load Sample Data: ``Yes``
       - Open Shell: ``No``
 
+      .. note::
+
+         The password is a random autogenerated value. ``abcdef12345`` 
+         is an example value.
+         
       .. io-code-block::
 
          .. input::