Add Github workflow badges

Author: sandeepmistry

README.md

@@ -1,5 +1,7 @@
 # ArduinoBLE
 
+[![Compile Examples Status](https://github.com/arduino-libraries/ArduinoBLE/workflows/Compile%20Examples/badge.svg)](https://github.com/arduino-libraries/ArduinoBLE/actions?workflow=Compile+Examples) [![Spell Check Status](https://github.com/arduino-libraries/ArduinoBLE/workflows/Spell%Check/badge.svg)](https://github.com/arduino-libraries/ArduinoBLE/actions?workflow=Spell+Check)
+
 Enables BLE connectivity on the Arduino MKR WiFi 1010, Arduino UNO WiFi Rev.2, Arduino Nano 33 IoT, and Arduino Nano 33 BLE.
 
 This library supports creating a BLE peripheral and BLE central mode.