Option to store arrow_filenames in window state

[farnoy]

I think this plugin is close to my ideal workflow, thanks for publishing it!

The only thing I'm missing and would like to try out is to store the list of files on the window, and not globally. I think this can be done with nvim_win_set_var(0, "arrow_filenames", ...) instead of vim.g.arrow_filenames = ... and so on.

One could then configure a workflow where separate windows (like panes and tabs) have independent sets of filenames to switch between.

WDYT about this idea and would a contribution adding a new opt-in setting for this mode be welcome?