doc: add go-tour-kr, a Korean translation of A Tour of Go
doc: add go-tour-kr, a Korean translation of A Tour of Go

R=golang-dev, dsymonds
CC=golang-dev
http://codereview.appspot.com/5273043

tav/go,tav/go,tav/go,tav/go,tav/go,tav/go,tav/go