WI-FI: connection through CLI

First, ensure that the computer/sbc has WI-FI parts.

install wpa_supplicant, edit /etc/wpa_supplicant/wpa_supplicant.conf, with ssid & psk.

Then run wpa_supplicant -i wlan0 -c /etc/wpa_supplicant/wpa_supplicant.conf & to connect to the named ssid.

ip a add ipv4-addr

ip r add default gw