Made the built-in example command a bit more interesting.

I added a default behaviour to the archetype's command example. This seems sensible because:

* The plugin the archetype generates can be tested against Spout's command system without being modified first (similar to the config.yml file having some default content).
* It teaches potential plugin developers a bit more about how Spout's command system works without being intrusively specific.

Atheriel <atheriel@gmail.com>