📝 Indicate custom implementation contribution in docs

Author: AlexV525

README-ZH.md

@@ -19,6 +19,9 @@ Language: [English](README.md) | 中文简体
 
 所有的界面细节基于 微信 7.x 版本，将在微信版本更新后随时进行跟进。
 
+**贴士：** 如果你觉得你的自定义实现会在某些程度上帮助其他人实现他们的需求，你可以通过 PR 提交你的实现。
+更多信息请参考 [贡献自定义实现](example/lib/customs/CONTRIBUTING.md) 。
+
 ## 目录 🗂
 
 * [迁移指南](#迁移指南-)

README.md

@@ -23,6 +23,9 @@ To take a photo or a video for assets, please check the detailed usage in the ex
 
 All UI designs are based on WeChat 7.x, and it will be updated following the WeChat update in anytime.
 
+*Note:* You can file PRs to create your own implementation if you found your implementation might be useful for others.
+See [Contribute custom implementations](example/lib/customs/CONTRIBUTING.md) for more details.
+
 ## Category 🗂
 
 * [Migration Guide](#migration-guide-)