Add key release

Author: amoghahs12

micropython/usb/usb-device-keyboard/usb/device/keyboard.py

@@ -75,9 +75,7 @@ def release_all(self):
         if self.send_report(self._key_reports[0], 200):
             return True
         return False
-    
     '''Example usage
-
     k = KeyboardInterface()
     usb.device.get().init(k, builtin_driver=True)
     key = [4] #It clicks letter A (refer KeyCode class)