Update ESP32_Keyboard_PPT_RC.ino

Author: fustyles

ESP32_Keyboard_PPT_RC.ino

@@ -6,6 +6,9 @@ https://www.facebook.com/francefu
 Library: 
 https://github.com/T-vK/ESP32-BLE-Keyboard
 
+Keyboard Modifiers and Special Keys
+https://www.arduino.cc/reference/en/language/functions/usb/keyboard/keyboardmodifiers/
+
 Command Format :  
 http://APIP/?cmd=P1;P2;P3;P4;P5;P6;P7;P8;P9
 http://STAIP/?cmd=P1;P2;P3;P4;P5;P6;P7;P8;P9