Input event modification chaining

Karabiner-Elements treats input events by the following order:

1. Catch events from hardware.
2. Apply Simple Modifications.
3. Apply Complex Modifications.
4. Apply Function Keys Modifications. (change f1…f12 keys to media controls)
5. Apply System Settings > Keyboard > Keyboard Shortcuts… > Modifier Keys.
6. Post events to applications via a virtual keyboard.