This is a Docker image containing DNSCrypt Proxy 2.x. You can use this to set up a DNS server on your local network which resolves queries using DNSCrypt or DNS-over-HTTPS (DoH) rather than sending plaintext DNS queries over the Internet.
You can run with this configuration:
docker run -p 53:53/udp -v /path/to/dnscrypt-proxy.toml:/config bltfqx/dnscrypt-proxy-2