Add 'CARDPUTER CircuitPython/wifi_switcher/readme.md'

CARDPUTER CircuitPython/wifi_switcher/readme.md

+# set up
+- write ssid and password pairs in settings.toml, the variable names dont matter at all
+- put those variable names into the "wifi options" list in code.py
+- don't need to touch the rest of the code, and you can add more items or delete items from the list, the menu screen will adjust accordingly
+
+# to do / notes
+- esc button bypasses any need to connect to wifi - although maybe dont include this in offline projects :P 
+- since you can choose, this makes cardputer basically portable since i can turn on hotspot