Document that --network excludes roles from wp user list output (#597)

* Initial plan

* Document that --network excludes roles field in wp user list

Co-authored-by: swissspidy <841956+swissspidy@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: swissspidy <841956+swissspidy@users.noreply.github.com>

Author: Copilot

features/user-list.feature

@@ -27,6 +27,20 @@ Feature: List WordPress users
       bobjones
       """
 
+  Scenario: List network users excludes roles field
+    Given a WP multisite install
+    And I run `wp user create bobjones bob@example.com --role=author`
+
+    When I run `wp user list --network --format=csv`
+    Then STDOUT should contain:
+      """
+      ID,user_login,display_name,user_email,user_registered
+      """
+    And STDOUT should not contain:
+      """
+      roles
+      """
+
   @require-wp-4.9
   Scenario: List users without roles
     Given a WP install

src/User_Command.php

@@ -71,7 +71,7 @@ public function __construct() {
 	 * : Control output by one or more arguments of WP_User_Query().
 	 *
 	 * [--network]
-	 * : List all users in the network for multisite.
+	 * : List all users in the network for multisite. Roles are not included when using this flag, as users can have different roles on different sites in a multisite network.
 	 *
 	 * [--field=<field>]
 	 * : Prints the value of a single field for each user.