[x/tour] go-tour: link to French translation
[x/tour] go-tour: link to French translation

Fixes #61.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/9592045
X-Tour-Commit: c28dee094f9029e79ac9f33f822cab3022f9dc51

golang/website,golang/website,golang/website,golang/website,golang/website,golang/website,golang/website