Update README.md

Author: HWHardsoft

README.md

@@ -12,7 +12,7 @@ Useful to test our [MBUS shield](https://www.hwhardsoft.de/english/projects/m-bu
 
 [Arduino MKR of your choice](https://store.arduino.cc/)
 
-[MBUS shield](https://www.hwhardsoft.de/english/projects/m-bus-mkr-shield/)
+[MBUS Master shield](https://www.hwhardsoft.de/english/projects/m-bus-mkr-shield/)
 
 MBUS device (meter) of your choice