Consider transitioning all graphs from Visio to Mermaid

[Chris-Turner-NIST]

User Story:

Mermaid is a tool that can be used to visualize the Vulntology Graphs using text representations within GitHub. We may be able to leverage this tool to allow easier tracking of changing to any graphs and to easily reference portions of the graphs within other sections of the Vulntology documentation.

Goals:

Review Mermaid and determine whether or not this is a good direction to go.
Redo the Vulntology Graph within mermaid to ensure we can retain all the current complexity we feel is important to convey.

Dependencies:

N/A

Acceptance Criteria

• All readme documentation affected by the changes in this issue have been updated.
• A Pull Request (PR) is submitted that addresses the goals of this User Story. This issue is referenced in the PR. If the PR only partially addresses a given User Story, the specific goals addressed are identified in the PR.
• All current graphs are updated using Mermaid and all informational items within specification section are updated to reflect the appropriate graph portion

{The items above are general acceptance criteria for all User Stories. Please describe anything else that must be completed for this issue to be considered resolved.}

[Crashedmind]

https://plantuml.com/ is a LOT more powerful and featureful than Mermaid (which is a pro and a con depending on what you're trying to do).
E.g. blocks or sections of diagrams can be defined in separate files and then included into other files/diagrams.

Main disadvantage is that it is not natively supported in Github - so the diagrams-as-text have to be rendered to images. Many Markdown tools support Plantuml so take care of this for you.

PlantUML also supports architecture/icon diagrams per https://crashedmind.github.io/PlantUMLHitchhikersGuide/
(Disclaimer: I wrote this guide)