Like a for-next loop, will loop from start to finish incrementing or
decrementing by 1 each time through. The value of the loop variable is
places in %0, and can be used in the command(s). If start>finish, it will
loop backwards.
examples:
#loop {1,3} {get all %0.corpse}
equivalent to the following:
get all 1.corpse;get all 2.corpse;get all 3.corpse
#loop {3,1} {drop %0.key}
equivalent to
drop 3.key;drop 2.key;drop 1.key