Attrset that is converted and passed as TOML config file.
For available params, see: <https://github.com/DNSCrypt/dnscrypt-proxy/blob/${pkgs.dnscrypt-proxy2.version}/dnscrypt-proxy/example-dnscrypt-proxy.toml>
For available params, see: <https://github.com/DNSCrypt/dnscrypt-proxy/blob/${pkgs.dnscrypt-proxy.version}/dnscrypt-proxy/example-dnscrypt-proxy.toml>