docs: add deepwiki documentation tip to README

Author: LujiaJin

README.md

@@ -4,6 +4,12 @@
 
 **A Gemini 2.5 Flash Level MLLM for Vision, Speech, and Full-Duplex Multimodal Live Streaming on Your Phone**
 
+</div>
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+<sub>💡 **Tip**: If you find this repository's structure or content difficult to understand, visit [deepwiki](https://deepwiki.com/LujiaJin/MiniCPM-o) for a comprehensive detailed explanation.</sub>
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+<div align="center">
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   <strong>[中文](./README_zh.md) |
   English</strong>