gotour: link to Chinese translation of A Tour of Go

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/5410044
diff --git a/static/index.html b/static/index.html
index 0c5c381..5152905 100644
--- a/static/index.html
+++ b/static/index.html
@@ -109,6 +109,7 @@
 	<p>
 	The tour is available in other languages:
 	<ul>
+	<li><a href="http://go-tour-zh.appspot.com/">Chinese &mdash; 中文</a></li>
 	<li><a href="http://go-tour-jp.appspot.com/">Japanese &mdash; 日本語</a></li>
 	<li><a href="http://go-tour-kr.appspot.com/">Korean &mdash; 한국어</a></li>
 	</ul>