"999 is enough for anybody" triple-zero padding (#18)

When I hit 999 exercises, I will finally have reached the ultimate
state of soteriological release and no more exercises will be needed.
The cycle will be complete. All that will be left is perfect quietude,
freedom, and highest happiness.

exercises/18_functions.zig

@@ -1,33 +0,0 @@
-//
-// Functions! We've already seen a lot of one called "main()". Now let's try
-// writing one of our own:
-//
-//     fn foo(n: u8) u8 {
-//         return n + 1;
-//     }
-//
-// The foo() function above takes a number "n" and returns a number that is
-// larger by one.
-//
-// If your function doesn't take any parameters and doesn't return anything,
-// it would be defined like main():
-//
-//     fn foo() void { }
-//
-const std = @import("std");
-
-pub fn main() void {
-    // The new function deepThought() should return the number 42. See below.
-    const answer: u8 = deepThought();
-
-    std.debug.print("Answer to the Ultimate Question: {}\n", .{answer});
-}
-
-// Please define the deepThought() function below.
-//
-// We're just missing a couple things. One thing we're NOT missing is the
-// keyword "pub", which is not needed here. Can you guess why?
-//
-??? deepThought() ??? {
-    return 42; // Number courtesy Douglas Adams
-}