Docs/update c4 diagrams

[K-Beicher]

Description

• This PR updates the two high-level C4 documents, moving away from docker containers and into four separate web applications.

Related Issues

Closes #87

Testing

• [x] Yes
• [ ] No, not needed (give a reason below)
• [ ] No, I need help writing them

Reviewer Focus

This PR requires an in-depth review.

Checklist

For general documentation:

• [x] Spell-check
  • [ ] US
  • [ ] UK
• [ ] Did the page(s) preview correctly on your machine without breaking
• [ ] New category words (keywords) (if any) added to the code snippet file

[signekb]

They now look like this:

Context

Container

[signekb]

@lwjohnst86 I couldn't find a way to remove the boundaries (a.k.a. the []) from the legend, so I kept them there for now. Then we can come back to it later, if we find it too frustrating to look at. But for now, I think we should just get these updated c4 diagrams merged.