This blog is a static blog and uses GitHub pages, GitHub pages are generally deployed using Jekyll.
How can you generate a sitemap without Jekyll plugin?
This gist answers your question.
I use some post values: changefreq, date and priority, if you don’t set any specific values for them default values are used that are, 0.8 for priority and month for frequency.
In a single post you add this params for use correct params!
If you want to know more about the Sitemap Protocol read this.
Marco thanks for English! :)