nixos/slskd: fix documentation link formatting

Changed files
+1 -1
nixos
modules
services
web-apps
+1 -1
nixos/modules/services/web-apps/slskd.nix
···
Web interface credentials should also be set here in `SLSKD_USERNAME` and `SLSKD_PASSWORD`.
Other, optional credentials like SOCKS5 with `SLSKD_SLSK_PROXY_USERNAME` and `SLSKD_SLSK_PROXY_PASSWORD`
should all reside here instead of in the world-readable nix store.
-
Variables are documented at https://github.com/slskd/slskd/blob/master/docs/config.md
+
Variables are documented at <https://github.com/slskd/slskd/blob/master/docs/config.md>
'';
};