ButtonHandler.md

@@ -2,6 +2,7 @@
 The **ButtonHandler** is a button observer: it reacts when a button is pressed.
 
 In particular when the ButtonHandler is trigger it calls a callback function (that is passed to its constructor) which is defined as:
+
 ```cpp
 using ButtonCallback = std::function<void(uint8_t, ButtonPress)>;
 ```