Stop using deprecated interfaces

Use `Kaleidoscope.use` and `Kaleidoscope.useEventHandlerHook` instead of the
deprecated `USE_PLUGINS` and `event_handler_hook_use` interfaces.

Signed-off-by: Gergely Nagy <kaleidoscope@gergo.csillger.hu>

README.md

@@ -37,7 +37,7 @@ enabling the plugin:
 #include <Kaleidoscope-SpaceCadet.h>
 
 void setup() {
-  USE_PLUGINS(&SpaceCadetShift);
+  Kaleidoscope.use(&SpaceCadetShift);
 
   Kaleidoscope.setup();
 }

examples/SpaceCadet/SpaceCadet.ino

@@ -40,7 +40,7 @@ const Key keymaps[][ROWS][COLS] PROGMEM = {
 };
 
 void setup() {
-  USE_PLUGINS(&SpaceCadetShift);
+  Kaleidoscope.use(&SpaceCadetShift);
 
   Kaleidoscope.setup();
 }

src/Kaleidoscope/SpaceCadet.cpp

@@ -30,7 +30,7 @@ SpaceCadetShift::SpaceCadetShift() {
 }
 
 void SpaceCadetShift::begin() {
-  event_handler_hook_use(eventHandlerHook);
+  Kaleidoscope.useEventHandlerHook(eventHandlerHook);
 }
 
 Key SpaceCadetShift::eventHandlerHook(Key mapped_key, byte row, byte col, uint8_t key_state) {