Add Bounce2 header to examples. Due to an annoying quirk with Arduino, we only include library headers directly referenced by the sketch, so dependencies have to be listed explicitly.

examples/complex_switch_panel/complex_switch_panel.ino

@@ -2,6 +2,7 @@
 // This is the code used in the Black Box project.
 // TODO: add link to blog post, once it exists.
 
+#include <Bounce2.h>
 #include <Joystick.h>
 
 Joystick joystick;