REQ: Add '--polling X' feature to support terminal dashboard use and persistent display

in reference to https://github.com/Canop/dysk/issues/71

Perhaps a solution is to provide an option to keep dysk open and redisplay the output polling every X seconds (default to 300 or 5 mins).

Some users may have a tmux session going for monitoring and may want to display dysk in a pane for example as part of their real time storage dashboard. The Watch command (commonly used) strips colors (considered a redirect) and there may be workarounds via piping and other complex chains other tools (neowatch) but it strikes me as cleaner coding and memory safe to load once and persist. From an enterprise perspective, even if something like neowatch 'dysk' would work, I'd have two software packages that need to be approved now assuming neowatch isn't in the standard software stack.

Other options for a name could be --dashboard-mode or --persist etc...