Add solutions

exercises/026_hello2.zig

@@ -23,5 +23,5 @@ pub fn main() !void {
     // to be able to pass it up as a return value of main().
     //
     // We just learned of a single statement which can accomplish this.
-    stdout.print("Hello world!\n", .{});
+    try stdout.print("Hello world!\n", .{});
 }