Fix expired Discord link

README.md

@@ -2,7 +2,7 @@
 
 [![Build Status](https://github.com/adafruit/Adafruit_IO_Arduino/workflows/Arduino%20Library%20CI/badge.svg)](https://github.com/adafruit/Adafruit_IO_Arduino/actions)[![Documentation](https://github.com/adafruit/ci-arduino/blob/master/assets/doxygen_badge.svg)](http://adafruit.github.io/Adafruit_IO_Arduino/html/index.html)
 
-[![Discord](https://img.shields.io/discord/327254708534116352.svg)](https://discord.gg/nBQh6qu)
+[![Discord](https://img.shields.io/discord/327254708534116352.svg)](https://adafru.it/discord)
 
 ![AIOArduino](https://cdn-learn.adafruit.com/assets/assets/000/057/496/original/adafruit_io_AIOA.png?1531335660)
 
@@ -22,4 +22,4 @@ for details).
 
 Adafruit invests time and resources providing this open source code, please
 support Adafruit and open-source hardware by purchasing products from
-[Adafruit](https://www.adafruit.com)!
+[Adafruit](https://www.adafruit.com)!