Split panes in a single window

[adam-c-anderson]

The current functionality to open a new window side-by-side is nice, but it's a little awkward to have two different windows open, plus they aren't guaranteed to remain next to each other in the host OS' app switcher list. It'd be nice to borrow Vim's language to create splits with :s and :vs. Then support navigation to those other splits as described in window-move-cursor

[ma3yta]

better to have two panels interface like https://fman.io/

https://github.com/mattstermiller/koffee/issues/68

[mattstermiller]

The ability to horizontally and vertically split panes is much more flexible and useful IMO. Making the app always two panes split vertically doesn't make sense to me when the dynamic approach is about the same amount of work to implement.

[mattstermiller]

When making this feature, a setting should be added to remember the split panes so that you can set up and keep splits across sessions (off by default).

This may have to be combined with the notion of opening the previous session's path or a default, since splits introduce multiple current paths.