Updated Chinese translation URL.

Author: SamYin Kim

documentation/tspl/index.md

@@ -31,7 +31,7 @@ We encourage you to participate in translating _The Swift Programming Language_
 Get involved with an existing translation project, or start a new one.
 
 <div class="links links-external links-list-nostyle" markdown="1">
-- [Read Chinese translation](https://swiftgg.gitbook.io/swift){:target="_blank"}
+- [Read Chinese translation](https://doc.swiftgg.team){:target="_blank"}
 - [Read Japanese translation](https://www.swiftlangjp.com){:target="_blank"}
 - [Read Korean translation](https://bbiguduk.gitbook.io/swift){:target="_blank"}
 - [Read Ukrainian translation](https://book.swift.org.ua){:target="_blank"}