Covers the use case where needing to exclude more than 1 output but
still include all other displays.
e.g. I have 3 monitors: laptop + HD + 4K; and 3 bar types:
- The main bar is on the laptop. `output: "laptop-monitor-id"`
- The 4K has a specific waybar bar-1 configuration. `output: "4K-monitor-id"`
- I want all other displays (3rd HD monitor / any HDMI output when presenting)
to have a plain bar: `output: ["!laptop-monitor-id", "!4k-monitor-id", "*"]`
Paul Riou