Add --show-layout flag

[Valkyrihane]

This flag displays the current keyboard layout next to the time.

Intends to close #107

Very small changes in order to display the keyboard layout on the lockscreen as cleanly as possible. The perfect way to do it would be to change the size of the rectangle on update(), but that is way too complex and unnecessary for an option like this in my opinion.

Another solution would be to use setxkbmap -query in order to always get two-letters code (us, fr, cn, ru, ...) and not i3lock's --keylayout option that displays (us, french, chinese, ...). Let me know what you think.

[zachkont]

I think that i3lock's --keylayout option is not live, meaning that it will not update the label if the layout is changed while the screen is locked

[Rizhiy]

I think that i3lock's --keylayout option is not live, meaning that it will not update the label if the layout is changed while the screen is locked

In https://github.com/Raymo111/i3lock-color it should be dynamic, see Raymo111/i3lock-color#167

[SebTM]

Thanks for your contribution, this will be resolved with the merge of the multi-monitor branch from multilockscreen-fork :)

[Valkyrihane]

Well, turns out I completely missed the PR approval notification 🤦‍♂️

Thanks for the heads-up @SebTM, I will thus delete my fork.
Cheers and keep up the good work! I am still using betterlockscreen daily

[SebTM]

No Problem, thanks for your support 👍🏻