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/switch_panel/switch_panel.ino

@@ -6,6 +6,7 @@
 // This example uses the *old* Joystick API. You should strongly prefer the
 // other, better examples in this directory!
 
+#include <Bounce2.h>
 #include <Joystick.h>
 
 bool debug = false;