"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/01_hello.zig

@@ -1,21 +0,0 @@
-//
-// Oh no! This program is supposed to print "Hello world!" but it needs
-// your help!
-//
-//
-// Zig functions are private by default but the main() function should
-// be public.
-//
-// A function is declared public with the "pub" statement like so:
-//
-//     pub fn foo() void {
-//         ...
-//     }
-//
-// Try to fix the program and run `ziglings` to see if it works!
-//
-const std = @import("std");
-
-fn main() void {
-    std.debug.print("Hello world!\n", .{});
-}