Update ble-cheat-sheet.md

Updates the Nano BLE Sense datasheet link in the user manual. Solves issue: #2655

Author: jhansson-ard

content/hardware/03.nano/boards/nano-33-ble-sense/tutorials/cheat-sheet/ble-cheat-sheet.md

@@ -45,7 +45,7 @@ The Nano 33 BLE Sense uses the [Arduino Mbed OS Nano Board Package](https://gith
 
 The full datasheet is available as a downloadable PDF from the link below:
 
-- [Download the Arduino Nano 33 BLE Sense datasheet](docs.arduino.cc/resources/datasheets/ABX00031-datasheet.pdf)
+- [Download the Arduino Nano 33 BLE Sense datasheet](https://docs.arduino.cc/resources/datasheets/ABX00031-datasheet.pdf)
 
 ## Installation