feat(ssh-keygen): add completion spec

[SerpentBytes]

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Adds missing completion specs.

What is the current behavior? (You can also link to an open issue here)

Currently missing completion specs for ssh-keygen command. Closes #1535.

What is the new behavior (if this is a feature change)?

Implement specs for ssh-keygen

Additional info:

See man ssh-keygen

First time contributing during Hacktoberfest.

[withfig-bot]

Overview

src/ssh-keygen.ts:

Info:

[withfig-bot]

Hello @SerpentBytes,
thank you very much for creating a Pull Request!
Here is a small checklist to get this PR merged as quickly as possible:

• Do all subcommands / options which take arguments include the args property (args: {})?
• Are all options modular? E.g. -a -u -x instead of -aux
• Have all other checks passed?

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[fedeci]

Thanks for this contribution @SerpentBytes! I just have one small comment to address.

[fedeci]

Thanks!

[SerpentBytes]

Thank you for allowing me to contribute to this project. 😊