include Adminpanel::Sitemap

When included, it's going to add callbacks after_create, after_destroy, and after_update for the resource, and in the callback is going to ping google, bing and ask about the sitemap.

The sitemap should be in www.yourhost.com/sitemap.xml a common implementation of that can be found here.

It's also recommended that you add your sitemap location in robots.txt with: Sitemap: http://example.com/sitemap_location.xml