Some users may want to switch buttons on their input devices, turns out
libinput already supports it. Let's add a support for it in our config.
Signed-off-by: Michał Winiarski <knr@hardline.pl>
Documents most of the bar commands in sway-bar(5) manpage.
The following command has not been document because they haven't been
fully implemented yet:
* mode
* hidden_state
* modifier
* tray_output
* tray_padding
Close#375