[Docs] - Add guide that shows how to order page index search results

[matthew-carroll]

Lists of pages often need to be displayed, such as the homepage for a blog.

We have a guide to search the index and show a directory of pages: https://staticshock.io/guides/directory-of-pages/

But that guide doesn't show how to order the results. Either add sorting to that guide, or write a new guide for that purpose.