docs: add centered ETH donation block and QR

Author: Teycir

README.md

@@ -1,3 +1,22 @@
+<!-- donation:eth:start -->
+<div align="center">
+
+## Support Development
+
+If this project helps your work, support ongoing maintenance and new features.
+
+**ETH Donation Wallet**  
+`0x11282eE5726B3370c8B480e321b3B2aA13686582`
+
+<a href="https://etherscan.io/address/0x11282eE5726B3370c8B480e321b3B2aA13686582">
+  <img src="publiceth.svg" alt="Ethereum donation QR code" width="220" />
+</a>
+
+_Scan the QR code or copy the wallet address above._
+
+</div>
+<!-- donation:eth:end -->
+
 <div align="center">
   <img src="assets/logo.svg" alt="DiffCatcher Logo" width="100%" />