Make 'includeAll' ordering more explicit

[JoshuaTheMiller]

The current documentation around the <includeAll> tag states that files are executed "alphabetically," which is great!

However, folks can have different opinions around what alphabetically ordered means. A simple example would be whether by default it implies ascending or descending order (i.e. from A to Z, or from Z to A).

For more widespread usage of this tool, it could prove beneficial to explicitly state the order, or ordering system, that is used. I realize that one could most likely determine this by digging through the source code, but having it on the doc site would be fairly nice 🙂