[DOCS] Docker settings are incorrects ?

[cyrilpawelko]

Just installed theengs/gateway image and running docker from command line with
Settings BLE_SCAN_TIME and BLE_TIME_BETWEEN_SCANS as stated on the docs have no effect.
Instead, I must use SCAN_TIME and TIME_BETWEEN as listed on https://github.com/maretodoric/theengsgateway-docker

https://github.com/theengs/gateway-docker/blob/main/chroot/opt/venv/start.sh effectively uses these parameters names.