ble: fix documentation endian
after merging:
https://git.card10.badge.events.ccc.de/card10/firmware/merge_requests/227 https://git.card10.badge.events.ccc.de/card10/firmware/merge_requests/242 https://git.card10.badge.events.ccc.de/card10/firmware/merge_requests/255
detailed in: https://git.card10.badge.events.ccc.de/card10/firmware/merge_requests/255