Nano ESP32 bootloader: mention B0 as well as B1

[pillo79]

Article URL
https://github.com/arduino/help-center-content/blob/main/content/Hardware%20Support/Nano%20Family/Reset-the-Arduino-bootloader-on-the-Nano-ESP32.md

Describe the problem with the article

Since the Nano ESP32 was released, I've seen a few people on the forums that I was not able to help. They complained of having followed the recovery guide with no errors, but still could not recover their board.

I finally asked this user today to perform a slightly more complicated procedure, and it did help:
https://forum.arduino.cc/t/arduino-nano-esp32-stuck-in-firmware-bootloader-mode/1379132/14

This should definitely be mentioned in the Nano ESP32 guide. Not sure if we should have only one (more complex) procedure described, or if we should mention "in case of problems try also shorting B0 to GND".