Examples: README direct the user to the opengl_example

examples/README.txt

@@ -1,15 +1,18 @@
 
-directx9_example/
-    DirectX9 example (Windows only).
-	
-directx11_example/
-    DirectX11 example (Windows only).
-	
 opengl_example/
     OpenGL example, using GLFW + fixed pipeline.
     This is simple and should work for all OpenGL enabled applications.
+    Prefer following this example since it is the shortest one!
 
 opengl3_example/
     OpenGL exemple, using GLFW/GL3W + programmable pipeline.
     This uses more modern calls and custom shaders.
     I don't think there is an advantage using this over the simpler example, but it is provided for reference.
+
+directx9_example/
+    DirectX9 example, Windows only.
+	
+directx11_example/
+    DirectX11 example, Windows only.
+    This is quite long and tedious, because: DirectX11.
+