docs(cn): update docs with info about GDPR (#515)

Author: ulivz

Diff for: docs/config/README.md

@@ -77,7 +77,9 @@ Specify the output directory for `vuepress build`.
 
 Provide the Google Analytics ID to enable integration.
 
+::: tip
 Please be aware of [GDPR (2018 reform of EU data protection rules)](https://ec.europa.eu/commission/priorities/justice-and-fundamental-rights/data-protection/2018-reform-eu-data-protection-rules_en) and consider setting Google Analytics to [anonymize IPs](https://support.google.com/analytics/answer/2763052?hl=en) where appropriate and/or needed.
+:::
 
 ### serviceWorker
 

Diff for: docs/zh/config/README.md

@@ -77,6 +77,10 @@ module.exports = {
 
 提供一个 Google Analytics ID 来使 GA 生效。
 
+::: tip 提示
+请留意 [GDPR (2018年欧盟数据保护规则改革)](https://ec.europa.eu/commission/priorities/justice-and-fundamental-rights/data-protection/2018-reform-eu-data-protection-rules_en), 在合适或者需要的情况下，考虑将 Google Analytics 设置为[匿名化的 IP](https://support.google.com/analytics/answer/2763052?hl=zh-Hans)。
+:::
+
 ### serviceWorker
 
 - 类型: `boolean`