Documentation Update: Control Representations in SSP

[brian-ruf]

User Story:

As an OSCAL SSP author, I need to understand options for representing controls that meet various organizational needs and circumstances, such as representing control responses for a whole control compared to representing content for individual statements within a control.

Goals:

• Identify scenarios for control representation
• Provide diagrams, examples, and explanations for each scenario
• Clarify the least and most granular states (one component at the control vs. multiple components at the statement level)
• Describe the transition from less granular to more granular.

Dependencies:

None.

Acceptance Criteria

• [ ] All OSCAL website and readme documentation affected by the changes in this issue have been updated. Changes to the OSCAL website can be made in the docs/content directory of your branch.
• [ ] A Pull Request (PR) is submitted that fully addresses the goals of this User Story. This issue is referenced in the PR.
• [ ] The CI-CD build process runs without any reported errors on the PR. This can be confirmed by reviewing that all checks have passed in the PR.

[david-waltermire]

This will be addressed by the tutorials resulting from #654.

[aj-stein-nist]

Marking this as blocked until #1910 is completed, and then it will be ready for "Needs Refinement" and determination if we edit this issue or replace it with a different one.