#146: Add option to display ProxyJump parameter

[campbell-brown]

Issue

#146

Description

There is an existing --show-proxy-command option. As per this guide, ProxyJump is more popular and recommended over ProxyCommand:

ProxyJump is the easiest and recommended way to jump between hosts because it ensures that traffic passing through the intermediate hosts is always encrypted end-to-end.

This PR adds an option to show ProxyCommand:

Example running:

cargo run -- --show-proxy-jump --config config-example