User and Contributor Oriented Architecture Guides

[mpstefan]

As a cluster operator using NGF
I want architecture documentation that both explains a high level overview of NGF's architecture
And I want a developer-oriented guide to NGF architecture
So that I can understand how to maintain NGF and how to contribute to the project.

Background

The current architecture documentation for NGF is written and presented in a way for a new user or developer to be able to understand.

Some feedback on issues with the current documentation:

• The Mermaid diagrams have small font and include too much information per diagram.
• The relationship NGF has with the Kubernetes API is dubious just looking at the Diagram.
• No clearly visible explanation of what our control and data planes are despite using the terms consistently throughout.
• No sequence diagrams for config changes, traffic, etc
• Gateway API objects do not reference the Kubernetes API in the diagram.
• The component overview section seems to mix sequence and general descriptions.

To solve some of these issues, we will likely need two separate architecture documents:

• One document available on docs.nginx.com with a broad overview intended for users of NGF.
• Another document available in our developer documentation on GitHub intended for contributors of NGF.

Why this is needed:
So new developers and users can quickly understand our architecture without giving up and/or seeking a new product.

Acceptance

• Two documents are created that explain NGF's architecture for users and contributors respectively.

[mpstefan]

@tataruty was I able to summarize the feedback well enough?