Provide screen-reader-friendly Vertical Layout

Zulip-terminal uses a "TUI", i.e. vertical splits of the terminal, to provide an intuitive user experience. Unfortunately, screen readers read, on the command line, the screen from left to right, hence mixing all vertical splits into a single one, when navigating the screen line by line. This renders the UI unusable.

For screen readers, a vertical split works much better (compare irssi, mutt, ...). If the different windows could be displayed from top to bottom, it would make this application accessible.

Screens are usually wider these days, so this would likely be an optional feature, but I would appreciate if this could be considered, as this would allow me to use Zulip.