Add field on the inicial configuration for hostname

[ffrediani]

After the initial configuration and reboot the NerdMiner connects to Wifi and asks for an IP address to DHCP identifying itself with its default hostname (eg: esp32s3-XXXX). Where there are several units running it would be useful to be able to give it a better hostname that identifies itself in order to help for maintenance and replacement.

Can you add an optional filed to fill a hostname for the device ?