static-ish files in rails, while allowing for nesting

pages_controller.rb

class PagesController < ApplicationController

  before_action :authorize!, :only => [ :welcome ]

  def welcome
  end

  def show_doc
    begin
      render "/pages/docs/#{params[:page]}"
    rescue ActionView::MissingTemplate
      render template: "pages/404", status: 404
    end
  end

end

routes.rb

Rails.application.routes.draw do
  controller :pages do
    get :welcome
    get '/docs/*page', action: :show_doc
  end
end