2 changes to command line instructions.

[clstmbrly]

@lachellel This is an update to the SSH for UNIX/Linus procedures. Corrections made to 2 command line instructions.

[lachellel]

I'm going to commit the PR. Here are additions that I'm thinking should to be added:

intro should be updated This config is for the linux server.
Add user friendly background information.
Simple statements and highlights (using the alerts for example) covering:

• Your PIV authentication key pair and public cert is exactly like using a self-signed cert and key pair to SSH
• It's on hardware
• the core issues to enable are ensuring your workstation or jump server can recognize the credential and enabling the correct drivers on the client are included

[clstmbrly]

@lachellel Thanks for your additions and suggestions. We'll work on modifying the procedures. @godadada