TODO: add delete char
TODO: undo system
TODO: save the state on SIGINT
TODO: ctrlc module is not implemented for windows
TODO: sigaction(2) instead signal(2) for better potability
TODO: keep track of date when the item was DONE
TODO: fix empty object
DONE: can add in done panel
DONE: replace Vec2 to coord2d lib
DONE: add new items to TODO
DONE: delete items
DONE: edit the items
DONE: full vim keys
DONE: save system
DONE: delete in todo state
