docs: 添加2025年12月21日赞赏记录 (#346)

- 新增赞赏：陈懂，50.00 RMB，赞赏码，for 泡芙小姐
- 更新累计收到赞赏：749.99 → 799.99
- 更新12月收到赞赏合计：320.11 → 370.11
- 同步更新 README.md 和 README_EN.md 徽章数值

README_EN.md

@@ -5,7 +5,7 @@
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 [![Philanthropy](https://img.shields.io/badge/Philanthropy-CNY%20600.00-brightgreen?style=flat-square)](./DONATIONS.md)
-[![Gratitude](https://img.shields.io/badge/Gratitude-CNY%20749.99-blue?style=flat-square)](./DONATIONS.md)
+[![Gratitude](https://img.shields.io/badge/Gratitude-CNY%20799.99-blue?style=flat-square)](./DONATIONS.md)
 [![Docker Pulls](https://img.shields.io/docker/pulls/xpzouying/xiaohongshu-mcp?style=flat-square&logo=docker)](https://hub.docker.com/r/xpzouying/xiaohongshu-mcp)
 
 MCP for RedNote (Xiaohongshu) platform.