fix(guide): simplify directory structure

guide/english/swift/hello-world/index.md

@@ -0,0 +1,29 @@
+---
+title: Hello World Swift
+---
+
+ ## Hello World
+
+Only we have to add the method `print("Hello World")` (from the library UIKit) to the function `viewDidLoad()` of the class `ViewController:
+
+ ```Swift
+ import UIKit
+
+class ViewController: UIViewController {
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        // Do any additional setup after loading the view, typically from a nib.
+        
+        print("Hello World")
+        
+    }
+
+
+}
+ ```
+
+ ## Output:
+ ```
+ >Hello World
+ ```