Update README.

* Nano RP2040 also requires the `no_reset` flag.

Author: iabdalkader

README.md

@@ -13,7 +13,7 @@ This firmware uses [Espressif's IDF](https://github.com/espressif/esp-idf)
 1. Use `esptool` to flash the compiled firmware
 
 ## Notes
-If updating **Arduino UNO WiFi Rev. 2** NINA firmware via [SerialNINAPassthrough](https://github.com/arduino-libraries/WiFiNINA/blob/master/examples/Tools/SerialNINAPassthrough/SerialNINAPassthrough.ino) sketch then the `esptool` invocation needs to be changed slightly:
+If updating the NINA firmware for an **Arduino UNO WiFi Rev. 2** or **Arduino Nano RP2040** board via [SerialNINAPassthrough](https://github.com/arduino-libraries/WiFiNINA/blob/master/examples/Tools/SerialNINAPassthrough/SerialNINAPassthrough.ino) sketch, then the `esptool` invocation needs to be changed slightly:
 ```diff
 -  --baud 115200 --before default_reset
 +  --baud 115200 --before no_reset