Add the Salt user personas

What does this MR do?

This MR adds the final Salt user personas.

What issues does this PR fix or reference?

N/A

GitLab Pages preview

https://barbaricyawps.gitlab.io/docs-hub/

Merge requirements satisfied? (FOR REVIEWER USE ONLY)

• Verify the pipeline is passing
• Check rendered output to ensure formatting is correct for any special directives such as notes, tables, lists, and images
• Review new or modified topics to ensure they follow the style guide
• Review new or modified topics to ensure they follow the Writing Salt documentation (rST guide)