Apply suggestion to openappstack/__main__.py

openappstack/__main__.py

@@ -126,7 +126,7 @@ def main():  # pylint: disable=too-many-statements,too-many-branches,too-many-lo
     droplet_creation_group.add_argument(
         '--truncate-subdomain',
         action='store_true',
-        help=('Add a subdomain that is shorter than 56 characters'))
+        help=('Truncate subdomain so subdomain and domain are shorter than 56 characters.'))
 
     droplet_creation_group.add_argument(
         '--acme-staging',