Added Ex. 2, polished script, added LICENSE

01_hello.zig

@@ -1,47 +1,16 @@
-// Oh no! This program is supposed to print "Hello world!" but it has some
-// mistakes. Let's fix it.
 //
-// We're trying to import the Standard Library into the top level of our
-// application. The standard library is not named "foo", it is named "std".
+// Oh no! This program is supposed to print "Hello world!" but it needs
+// your help!
 //
-// Please correct the name in both places in the import here:
-const foo = @import("foo");
+// Hint: Zig functions are private by default.
+//       The main() function should be public.
+//       Declare a public function with "pub fn ..."
+//
+// Try to fix the program and run `ziglings` to see if it passes.
+//
+const std = @import("std");
 
-// Zig applications start by calling a function named 'main'. It needs to be
-// public so that it is accessible outside our file!
-//
-// Public functions are declared with the 'pub' keyword like so:
-//
-//     pub fn my_function() void { ... }
-//
-// Please make the main() function public:
 fn main() void {
-
-    // The easiest way to display our "Hello world" message in the
-    // terminal is to use the std.debug.print() function.
-    
-    // Please fix this silly "foo" mistake here:
-    foo.debug.print("Hello world!\n", .{});
-
-    // The print function above takes two values:
-    //
-    //   1. A string of characters: "Hello world!\n". "\n" prints a new line.
-    //
-    //   2. A struct containing data to be displayed. .{} is an empty, nameless
-    //      struct fulfilling the requirement. More about structs later.
-    //
-    //
-    // Now we're ready to...What's this!? Oh, we wanted to print a Goodbye
-    // message as well!
-    //
-    // Please fix this to use the same print function as above:
-    "Goodbye!\n"
+    std.debug.print("Hello world!\n", .{});
 }
 
-// Once you're done with the changes above, run `ziglings` to see if it passes.
-//
-// Finally, all files will contain the following comment:
-//
-// I AM NOT DONE
-//
-// Delete it when you're ready to continue to the next exercise!