Update readme.md

Signed-off-by: Adrian <[email protected]>

Author: adrian2793

readme.md

@@ -1,6 +1,6 @@
 # Serial Monitor
 
-[![](https://img.shields.io/badge/Available_in_the_Arduino_Library_Manager-2ea44f)](<Link>)
+[![](https://img.shields.io/badge/Available_in_the_Arduino_Library_Manager-2ea44f)](https://www.arduino.cc/reference/en/libraries/serial_monitor/)
 
 ## Get Started