Settings dot php

depends on #14 (iirc)

Per conversations with Doug, Greg, and Dana (maybe Maks as well), there's no reason we should have settings.php be dynamic. It's way better if it references something interoperable with a known path to find the thing with the configurable path (the config directory).

As such, there's now a file called env.json that's always in the same directory as settings.php and it just points to the settings config dir. It can do more though; it's json. If you define more things, it can be your dictionary. It can be your hash if you... like to party?