Clarify config var and add to LDAP docs.

config/gitlab.yml.example

@@ -146,7 +146,9 @@ production: &base
         # disable this setting, because the userPrincipalName contains an '@'.
         allow_username_or_email_login: false
 
-        # Locks down those users until they have been cleared by the admin (default: false).
+        # To maintain tight control over the number of active users on your GitLab installation,
+        # enable this setting to keep new users blocked until they have been cleared by the admin 
+        # (default: false).
         block_auto_created_users: false
 
         # Base where we can search for users

doc/integration/ldap.md

@@ -51,6 +51,11 @@ main: # 'main' is the GitLab 'provider ID' of this LDAP server
   # disable this setting, because the userPrincipalName contains an '@'.
   allow_username_or_email_login: false
 
+  # To maintain tight control over the number of active users on your GitLab installation,
+  # enable this setting to keep new users blocked until they have been cleared by the admin 
+  # (default: false).
+  block_auto_created_users: false
+
   # Base where we can search for users
   #
   #   Ex. ou=People,dc=gitlab,dc=example