Update README.md

Author: yushulx

src/README.md

@@ -1,5 +1,5 @@
 ### How to Build
-Download [Dynamsoft Barcode Reader SDK](https://www.dynamsoft.com/Downloads/Dynamic-Barcode-Reader-Download.aspx) for Linux, macOS and Raspberry Pi.
+Download [Dynamsoft Barcode Reader SDK v7.2.2](https://github.com/dynamsoft-dbr/python-barcode/releases/tag/v7.2.2) for Linux, macOS and Raspberry Pi.
 
 Copy **libDynamsoftBarcodeReader.so**/**libDynamsoftBarcodeReader.dylib** to `/usr/lib`. If you don't have access to `/usr/lib`, try to copy the library to `/usr/local/lib` and set the **LD_LIBRARY_PATH** as follows: