Create RSC dashboard markdown documents

[chrtorres]

🗣 Description

• Created new route within docs for RSC dashboard.
• Created markdown for RSC dashboard user guide.

💭 Motivation and context

This change is meant to guide incoming users new to the platform. With the deployment of ReadySetCyber, this will help users navigate the various items to access their assessments in an easy to find location.

This closes issue #207

📷 Screenshots (if appropriate)

✅ Pre-approval checklist

• This PR has an informative and human-readable title.
• Changes are limited to a single goal - eschew scope creep!
• I have read the CONTRIBUTING document.
• These code changes follow cisagov code standards.
• All relevant repo and/or project documentation has been updated
  to reflect the changes in this PR.
• All new and existing tests pass.

✅ Pre-merge checklist

• Revert dependencies to default branches.
• Finalize version.

✅ Post-merge checklist

• Create a release.

[nickviola]

LGTM

[cduhn17]

LGTM