Add examples for using ssh to install from Source Control

[tonur]

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Added an example for using ssh, in case you do not work with https credentials for private repositories.

The "<URL>.git" extension on https:// links also works for ssh:// links on GitHub, but not on Azure DevOps Repos, which is why it is removed from the example.

• [ ] I have added a news fragment under changelog.d/ (if the patch affects the end users) (Not Applicable)

Summary of changes

Added Bash code lines showcasing examples of installing from Source Control via ssh.

Test plan

Tested by running

# command(s) to exercise these changes
pipx install git+ssh://[email protected]/psf/black
pipx uninstall black
pipx install git+ssh://[email protected]/psf/black.git
pipx uninstall black