Create a procedure in scheme that will return a list containing the absolute value of the difference between z and each item in list.

For example:

scheme@(guile-user)> (diff 10 (8 9 10 11 12)) $2 = (2 1 0 1 2)

scheme@(guile-user)> (diff 10 (11 9 100 3 -4 10)) $3 = (1 1 90 7 14 0)