gsbot.go example is broken

[Nuc1eoN]

Currently the example gsbot.go does not compile:

$ go build gsbot.go 
# command-line-arguments
./gsbot.go:34:3: too few values in &gsbot.LogOnDetails literal

This seems to have been caused by bc3a0ce

EDIT: I have just used named fields for now, but since I am not sure how exactly the TwoFactorCode is to be used (either TwoFactor or AuthCode or do we need both?) this should probably be fixed in a different way for the example file. Also the description comment above might need adjustment to reflect how it is supposed to be used.

[Philipp15b]

If I remember correctly, AuthCode is used for email verification, and TwoFactorCode is used for mobile authentication via the Steam mobile app. Pull requests are appreciated!