Create pbj-while-loop-goal2

# Goal #2: Modify PBJ Goal 1 to say how many sandwiches-worth of each ingredient remains.

# Example 2:
# bread = 10
# peanut_butter = 10
# jelly = 4

# Output:
# Making sandwich #1
# I have enough bread for 4 more sandwiches, enough peanut butter for 9 more, and enough jelly for 3 more.
# Making sandwich #2
# I have enough bread for 3 more sandwiches, enough peanut butter for 8 more, and enough jelly for 2 more.
# Making sandwich #3
# I have enough bread for 2 more sandwiches, enough peanut butter for 7 more, and enough jelly for 1 more.
# Making sandwich #4
# All done; I ran out of jelly.