Merge pull request #848 from kenjis/docs-shield-user-command

docs: add about `shield:user` command

docs/user_management/managing_users.md

@@ -2,7 +2,9 @@
 
 Since Shield uses a more complex user setup than many other systems, separating [User Identities](../getting_started/concepts.md#user-identities) from the user accounts themselves. This quick overview should help you feel more confident when working with users on a day-to-day basis.
 
-## Creating Users
+## Managing Users by Code
+
+### Creating Users
 
 By default, the only values stored in the users table is the username. The first step is to create the user record with the username. If you don't have a username, be sure to set the value to `null` anyway, so that it passes CodeIgniter's empty data check.
 
@@ -26,7 +28,7 @@ $user = $users->findById($users->getInsertID());
 $users->addToDefaultGroup($user);
 ```
 
-## Deleting Users
+### Deleting Users
 
 A user's data can be spread over a few different tables so you might be concerned about how to delete all of the user's data from the system. This is handled automatically at the database level for all information that Shield knows about, through the `onCascade` settings of the table's foreign keys. You can delete a user like any other entity.
 
@@ -40,7 +42,7 @@ $users->delete($user->id, true);
 > **Note**
 > The User rows use [soft deletes](https://codeigniter.com/user_guide/models/model.html#usesoftdeletes) so they are not actually deleted from the database unless the second parameter is `true`, like above.
 
-## Editing a User
+### Editing a User
 
 The `UserModel::save()`, `update()` and `insert()` methods have been modified to ensure that an email or password previously set on the `User` entity will be automatically updated in the correct `UserIdentity` record.
 
@@ -56,3 +58,26 @@ $user->fill([
 ]);
 $users->save($user);
 ```
+
+## Managing Users via CLI
+
+Shield has a CLI command to manage users. You can do the following actions:
+
+```text
+create: Create a new user
+activate: Activate a user
+deactivate: Deactivate a user
+changename: Change user name
+changeemail: Change user email
+delete: Delete a user
+password: Change a user password
+list: List users
+addgroup: Add a user to a group
+removegroup: Remove a user from a group
+```
+
+You can get help on how to use it by running the following command in a terminal:
+
+```console
+php spark shield:user --help
+```