feat: allow custom design patterns

[jaulz]

This PR allows custom patterns to be registered via:

    $this->app->extend(ActionManager::class, function (ActionManager $actionManager) {
      $actionManager->registerDesignPattern(new FooBarDesignPattern());

      return $actionManager;
    });

[lorisleiva]

Thanks! FYI, you can also use the Facade to update the Action Manager like so.

use Lorisleiva\Actions\Facades\Actions;

Actions::registerDesignPattern(new FooBarDesignPattern());

[jaulz]

Ah, thanks for the merges and the hint 😊