Change exercise

_includes/binarization/exercises/binarization_imagejgui.md

-This file should contain language-specific exercises, *written* in **Markdown**
+### Exercise 1
 
-...but probably with some HTML mixed in, so that you can add expandable Solution boxes.
-
-#### Exercise 1
-
-What is the solution to the first exercise? 
+Please...
 
 <details>
 <summary>Solution</summary>
 This is the solution to the first exercise.
 </details>
 
-#### Exercise 2
+### Exercise 2
 
-What is the solution to the second exercise?
+Please...
 
 <details>
 <summary>Solution</summary>