Package Repository Installation Error in the Documentation

There is an error in the documentation (openHAB on Linux | openHAB).

According to the guide, you are saving the signing key as openhab.pgp while in the /etc/apt/sources.list.d/openhab.list you are defining the signed-by=/usr/share/keyrings/openhab.gpg, so you need to rename the extension of the openhab key to gpg in order to fix it, otherwise the system update fails.

Please fix your documentation.

and for explanation why it still is not shown yet: