These are provided for use in the editor. The Templates folder contains some stock rooms to help you design your own Aura mazes. The Cheaters folder contains all of the beta testing levels for you to peruse and abuse. The Test Suite contains tests of all the features of the Aura engine, any bug reports you find with them would be greatly appreciated.
The standard Allegro setup utility is included in the alsetup folder. It allows you do to some custom hardware configuration and stuff. You probably won't need it to run Aura, but it can't hurt to have it.
The file "aura.ea2" contains an environment designed for Aura. Currently, you must load it manually if you want it to take effect.