switch between vertical/horizontal split

[robinpecha]

Thanks for this amazing software. It helps me in many places daily. Really good work.
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢠⠒⢦⡀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠆⠀⣿⡇⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⢀⠞⢉⣽⡿⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⡠⠋⢐⣾⣷⠁⠀⠀⠀⠀⠀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⣰⠡⠤⣮⣿⣵⠆⠠⠤⣀⣀⡀⠀⠀
⠀⠀⠀⠀⠀⠀⠀⠀⠀⡰⠏⠀⠐⢾⣽⣛⠟⠚⠛⠓⠒⠈⠱⡄
⠀⣀⣀⣤⣀⣤⣄⠠⡜⠃⠀⢀⣀⣼⣿⣿⠿⢦⣶⣶⣦⣿⣿⡟
⣾⣿⣿⠻⢿⣿⡇⠀⢫⣣⡱⣾⡿⣿⣿⣿⣆⣄⢀⢉⡉⣩⣿⠀
⢻⢻⡿⡎⠀⠀⢇⣀⣬⣷⠉⠙⠉⠙⣻⣿⠙⠓⠛⠿⣿⣿⠟⠀
⢸⣄⠈⢧⠀⠀⠸⡀⢀⣿⣤⣀⠀⠀⣺⡟⠿⣶⢦⣦⣤⡿⠀⠀
⠀⢻⣷⣼⡄⠀⠀⢱⣿⡿⠿⠾⠷⣶⣿⣷⣦⣌⢉⣻⠏⠁⠀⠀
⠀⠀⢧⣿⣷⡤⠒⠓⠁⠀⠀⠀⠀⠀⠀⠀⠉⠉⠋⠁⠀⠀⠀⠀
⠀⠀⠈⣚⡻⠇⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

Maybe it could be a good feature to add another screen mode with half screen but in vertical split. Something like this:

Because right now I can split only horizontaly and its wasting lot of space: