Translate index.md to Chinese

No-Try: true
Docs-Preview: https://skia.org/?cl=24083
Bug: skia:
Change-Id: I6b3aaabfda26c8e0472e1dd9d9d9db0f6deeca5b
Reviewed-on: https://skia-review.googlesource.com/24083
Reviewed-by: Mike Klein <mtklein@chromium.org>
Reviewed-by: Joe Gregorio <jcgregorio@google.com>
Commit-Queue: Yuqian Li <liyuqian@google.com>
1 file changed