Rename module_supervisor.ex -> plugin/supervisor.ex, and PluginSupervisor -> Plugin.Supervisor

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

lib/plugin/supervisor.ex

@@ -1,4 +1,4 @@
-defmodule Omnibot.PluginSupervisor do
+defmodule Omnibot.Plugin.Supervisor do
   @moduledoc false
 
   use Supervisor

lib/supervisor.ex

@@ -16,7 +16,7 @@ defmodule Omnibot.Supervisor do
     children = [
       {Task.Supervisor, name: Omnibot.RouterSupervisor, strategy: :one_for_one},
       {Omnibot.State, cfg: cfg, name: Omnibot.State},
-      {Omnibot.PluginSupervisor, cfg: cfg, name: Omnibot.PluginSupervisor},
+      {Omnibot.Plugin.Supervisor, cfg: cfg, name: Omnibot.Plugin.Supervisor},
     ] ++ unless IEx.started?(),
       do: [{Omnibot.Irc, name: Omnibot.Irc}],
       else: []