Added mix commands to manage users and view actors

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/mix/tasks/mobilizon/users.ex

@@ -0,0 +1,14 @@
+defmodule Mix.Tasks.Mobilizon.Users do
+  @moduledoc """
+  Tasks to manage users
+  """
+  use Mix.Task
+
+  @shortdoc "Manages Mobilizon users"
+
+  @impl Mix.Task
+  def run(_) do
+    Mix.shell().info("\nAvailable tasks:")
+    Mix.Tasks.Help.run(["--search", "mobilizon.users."])
+  end
+end