update express starter guides @ 1.0

[ladyada]

its a todo for scott! plz update this guide to match 1.0
https://learn.adafruit.com/admin/guides/1615/editor/9140
this is shared between both feather & metro. thx :)

[tannewt]

Will do!

[tannewt]

Updated the guide by using led.direction = digitalio.Direction.OUTPUT instead of switch_to_output().