fix: add missing slug to CN quickstart page (#2906)

Fixes broken links in CN build:
- /guides/ was linking to /guides/deploy/quickstart
- /guides/products/dce was linking to /guides/deploy/quickstart

Added slug: /deploy/quickstart to match EN version.

Author: bohutang

docs/cn/guides/10-deploy/00-QuickStart/index.md

@@ -1,5 +1,6 @@
 ---
 title: 快速入门
+slug: /deploy/quickstart
 ---
 
 Databend 快速入门：5 分钟体验 Databend