Document connecting to `clickhouse client` using SSH.

[johnnymatthews]

It's possible to log into a Clickhouse client over SSH, rather than typical password auth. All the information we need is nicely packaged in this video.

The content should live under docs/en/managing-clickhouse/security/ssh-keys.md.

[kkarthislm]

@johnnymatthews it is already on production https://clickhouse.com/docs/en/guides/sre/ssl-user-auth

src : docs/en/guides/sre/user-management/ssl-user-auth.md

[mkmik]

@johnnymatthews it is already on production https://clickhouse.com/docs/en/guides/sre/ssl-user-auth

src : docs/en/guides/sre/user-management/ssl-user-auth.md

that doc is about SSL not SSH

[gingerwizard]

https://github.com/ClickHouse/clickhouse-docs/pull/2894