update-status event is emitted periodically (based on the
interval specified by the status_update_interval
The first event parameter is a
window object that
represents the gui window.
The second event parameter is a
pane object that
represents the active pane in that window.
wezterm will ensure that only a single instance of this event is outstanding;
if the hook takes longer than the
status_update_interval to complete,
wezterm won't schedule another call until
milliseconds have elapsed since the last call completed.