chore(docs): diagrams as code with likec4

[chance-coleman]

Description

We recently decided to use diagrams as code for creating and maintaining our diagrams. This should reduce maintenance burden and speed up creation of new diagrams.

Because this is diagrams as code, we lose some ability to customize how the diagram is generated. There is the ability with likec4 to manually edit and arrange diagrams, however doing this has some big pitfalls:

1. It causes headaches anytime we update the diagrams because the generator is not smart enough to take the customizations and add new things elegantly
2. When exporting the manually created diagrams, the export functionality is not smart enough to figure out where the center of the diagram is, resulting in a very large capture space which is mostly just white space.

Currently created diagrams:

• Overview Diagrams
  • Basic Overview
  • Namespace Overview
  • Ingress / Egress Overview
• Functional Layers (each layer is it's own diagram)
• Namespaces (each namespace is it's own diagram)
• Ports and Protocols

Open Questions

• How do we like the colors?
• Do we want all these diagrams to be generated and stored in UDS Core right? Or do we only want a subset of them?
• Does anyone have any experience with likec4 and how to make manually customized diagrams export the right size? Or some automated way of trimming whitespace from a png?

Related Issue

Fixes #1955

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• Test, docs, adr added or updated as needed
• Contributor Guide followed

[slaskawi]

The diagrams look better than I initially thought! :)

Could we update the colors (especially that red-ish one) to match the UDS Registry branding?

[slaskawi]

Added one comment and wanted to suggest adding a short ADR with a compiled version of arguments why we switched to C4. Otherwise, LGTM

[joelmccoy]

This is looking awesome!

Haven't done an in depth review yet but a couple comments/questions at a first pass:

1. If the image files are changing frequently, do you think it is worth starting to store these images in git lfs? (might save us some pain down the line as the git history of uds-core grows)
2. I think we can get rid of the namespace views based on another comment (not providing too much value IMO)
3. I think it is fine for the functional layer views to only contain the components delivered in that layer

Other than that, I think this is looking pretty solid

[joelmccoy]

Generally lgtm! Add a few comments for consideration