Add ESP32-S3 to compat list

README.md

@@ -11,6 +11,6 @@ Currently supports the following hardware:
 *  Arduino Leonardo or other 32u4-based boards (e.g. Adafruit Feather) WITH CAVEAT: USB Serial connection is clobbered on sleep; if sketch does not require Serial comms, this is not a concern. The example sketches all print to Serial and appear frozen, but the logic does otherwise continue to run. You can restore the USB serial connection after waking up using `USBDevice.attach();` and then reconnect to USB serial from the host machine.
 *  Partial support for Teensy 3.X and LC (watchdog, no sleep).
 *  ATtiny 24/44/84 and 25/45/85
-*  ESP32, ESP32-S2
+*  ESP32, ESP32-S2, ESP32-S3
 *  ESP8266 WITH CAVEAT: The software and hardware watchdog timers are fixed to specific
 intervals and not programmable. Notes about this are within the `utility/WatchdogESP8266.cpp` file.