[zh] Sync contribution guidelines (5)

This PR is about the reviews.

Author: tengqm

content/zh/docs/contribute/review/_index.md

@@ -0,0 +1,17 @@
+---
+title: 评阅变更
+weight: 30
+---
+<!--
+title: Reviewing changes
+weight: 30
+-->
+
+<!-- overview -->
+<!--
+This section describes how to review content.
+-->
+本节描述如何对内容进行评阅。
+
+<!-- body -->
+