add graveyard subcommand + help colors

[MilesCranmer]

Easy way to get graveyard path:

rip graveyard

so you can easily check the sizes of its contents with:

ls -lath $(rip graveyard)

or of the current folder with

ls -lath $(rip graveyard -s)

@JeromeSchmied might help with #11. Maybe even a solution to it?

[JeromeSchmied]

yeah, it's cool