FR - Add information about how to sign releases

[gliwka]

Hi,

it would be great to add some information about how to sign releases, so they can be authenticated as well.

See https://wiki.debian.org/Creating%20signed%20GitHub%20releases as a reference. The gpg command in the instruction from the debian project would translate into keybase pgp sign -i FILENAME.EXT --detached to sign a file.

Best,
Matthias

[pstadler]

Contributions are welcome 👍🏻