Create a plan for usability testing with federal agencies onboarding to org model

[witha-c]

Sub-issue description

Separately from gathering open-ended and semi-structured feedback from users, we will plan for formal usability testing with users at federal agencies

Acceptance criteria

• Incorporate user recruiting into the plan for user feedback Create a user feedback plan for agencies onboarding to org model #3572
• Document the research plan
• Draft tickets for test material prep, testing, and analysis and reporting
• Coordinate with product on participants, ensuring we include non-admins (ie, domain managers) since most of our early conversations have been with admins

Additional context

This would be in lieu of onboarding walkthroughs for the agencies/users we do this with.