Add Bisq to Debian tool "extrepo"

[Rudy-MS]

The Issue:
Although I'm sure it's easier for most people but I find the PGP verification process for downloading Bisq a bit of a headache.

Solution:
It would be great to add a repository to the Debian tool call "extrepo". Please see --> https://wiki.debian.org/DebianRepository/Unofficial

Note: Bit of a newb but I am assuming that by having a curated repo that it would be just as safe as using PGP verification.