Singular Resources support

[stgeneral]

Add support or just a description for using https://guides.rubyonrails.org/routing.html#singular-resources.

[stgeneral]

Solution:

# config/routes.rb
resource  :org, only: [:show]

# app/controllers/orgs_controller.rb
class OrgsController < ResourcesController
  private

  def find_resource
    id_param.present? ? super : current_user.org
  end
end