SSHD configuration

Here are some secure algorithms (at the time of writing) to add in the /etc/ssh/sshd_config file:

Ciphers chacha20-poly1305@openssh.com
KexAlgorithms curve25519-sha256@libssh.org
MACs hmac-sha2-512-etm@openssh.com,hmac-sha2-256-etm@openssh.com