Update README.md

Author: atiksoftware

examples/SFML/README.md

@@ -1,5 +1,13 @@
 # Create SFML Overlay Transparent Window
-Create a window as transparent background and ctopmost and unclickable window form.
+Create a window as transparent background and top most and unclickable window form.  
+i think its more performance then directx about sprites and circle or rectange  
+and also you can draw text with outline color easly.
+
+you can find more example in:  
+https://www.sfml-dev.org/tutorials/2.4/graphics-shape.php
+
+Download SFML Library:  
+https://www.sfml-dev.org/download.php
 
 ```c++
 sf::RenderWindow window;