feat: donation

docs/preface.md

@@ -35,7 +35,7 @@ I am grateful to all friends who have contributed to this book and offered sugge
 
 My hope is that this book can help more people, enabling them to experience the joys of NixOS. I also wish for this book to benefit the NixOS community by encouraging more people to contribute to its development.
 
-The content of this book is continually being updated, with much room for improvement. I welcome everyone to provide suggestions and contribute on [GitHub](https://github.com/ryan4yin/nixos-and-flakes-book).
+The content of this book is continually being updated, with much room for improvement. Any suggestions are welcome, and contributions to the content on [GitHub](https://github.com/ryan4yin/nixos-and-flakes-book) are also highly encouraged.
 
 ## The Features of This Book
 
@@ -44,6 +44,16 @@ The content of this book is continually being updated, with much room for improv
 3. Step-by-step, progressive learning.
 4. Coherent content, well-organized, and structured. Readers can either read the book gradually or quickly find the information they need.
 
+## Donation
+
+If you find this book helpful, please consider donating to support its development.
+
+- Patreon: <https://patreon.com/ryan4yin>
+- Buy me a coffee: <https://buymeacoffee.com/ryan4yin>
+- 爱发电: <https://afdian.net/a/ryan4yin>
+- Ethereum: `0xB74Aa43C280cDc8d8236952400bF6427E4390855`
+
+
 ## Historical Feedback and Discussions on This Book
 
 English feedback and related discussions:

docs/zh/preface.md

@@ -55,6 +55,15 @@ Nixpkgs 源码等各种资料中提取出我需要的信息，同时还要忽略
 2. step-by-step，渐进式地学习
 3. 内容连贯，组织良好，比较成体系。读者既可以渐进式地阅读本书，也可以快速定位自己需要的信息
 
+## 捐赠
+
+如果你觉得这本书对你有帮助，请考虑捐赠以支持它的开发。
+
+- Patreon: <https://patreon.com/ryan4yin>
+- Buy me a coffee: <https://buymeacoffee.com/ryan4yin>
+- 爱发电: <https://afdian.net/a/ryan4yin>
+- Ethereum: `0xB74Aa43C280cDc8d8236952400bF6427E4390855`
+
 ## 本书的历史反馈与相关讨论
 
 英文反馈与相关讨论：