put code block in collapsible box

docs/Assignments/week_4_programming/programming.md

@@ -338,7 +338,7 @@ Im going to map everything lower than 80 to 80 using software. The reason im doi
 Luckily there is an arduino function called `map` that can do this. [Source](https://docs.arduino.cc/language-reference/en/functions/math/map/). The syntax is like this `map(value, fromLow, fromHigh, toLow, toHigh)` so it's really easy to use. This is how I implemented it. 
 
 During coding I realized this could be done way easier and simpler. So this is my result 
-
+??? code
     ```cpp
     #include <Arduino.h>