update changelog

Author: hathach

changelog.md

@@ -4,11 +4,12 @@
 
 ### Core
 
-- Make FreeRTOS run in tickless mode
+- Change FreeRTOS to tickless mode
 - Added systemOff() to enter System Off mode
 - Added suspendLoop() to disable loop() task to further save power
 - Correct waitForEvent() function with SoftDevice enabled and disabled.
 - Added RotaryEncoder support for both Hardware and Software Encoder.
+	- Software Encoder couldn't response fast enough due to gpio interrupt latency
 - Ada Callback task is started along with loop task, used as worker thread to defer interrupt callback.
 
 ### BLE