Feature request: Option to change monitor order

An option for the plugin in which you can specify what order you want it to assign your monitors in. It would look something like:

```
plugin {
    split-monitor-workspaces {
        monitor_order = DP-1,eDP-1
    }
}
```

This way it would be easier to handle keybinds when you can intentionally set specific monitors to specific workspaces.