Rendering system and component structure to a diagram

[butler54]

Issue description / feature objectives

This is speculative for discussion

SSPs typically have a large number of diagrams. Today that would be supported by an external image reference. The defacto way that is suggested under trestle is to use drawio and check it in as code.

However, drawio files, while xml, are from a SCM management PoV binary blobs. This brings two issues:

1. What "as code" image formats could be used.
2. If required to generate images from the oscal model (for example to build a diagram of the components and sub-components in an SSP). what format could be used.

At a high level mermaid.js is proposed as:

1. Support from major SCM makers (GitHub and GitLab) as an integrated extension of markdown
2. Is focused on IT including support for some UML flavours
3. Is not a drawing format. There are limited methods to manipulate the diagrams layout. While this might not be perfect for a sales deck.

Caveats / Assumptions

• As code implies that it's declarative as well where possible (e.g. gitops over shell scripts in github)

Completion Criteria

• An expermmental workflow showing how a mermaid diagram can be used in an SSP. Ideally with a word or pdf format output.

[jpower432]

@butler54 I think this might be related to #1617. Wondering if this could be an issue under this Epic. What do you think?