Improved conceptual introduction to AI Gateway

Jobs to be done

We don't provide a prominent big-picture overview of AI gateway. The existing quickstart just gives you minimal set up and tear down instructions without any motivation and the landing page speaks at a higer level of abstraction.

We often assume a degree of familiarity with LLM deployments but questions like:

• https://app.kapa.ai/93b55f65-cffb-4d0b-9da7-c8915a838dce/conversations/375b8143-e413-479b-bf91-19c3d1574419
  suggest we do need an introductory page.

We should describe a minimal proxying setup, highlighting how how Gateways, Providers, and Models are related. This should include a mermaid diagram. As an appendix talk about adding policies into this basic setup.

Definition of done

New overview page or additions to the landing page and quickstart.

Size

• L (Large) Example: adding an API/Terraform how to, writing a reference page, writing a how to that involves a known third-party product (like Okta or Auth0)

Review the existing quickstart and landing page to understand their current scope and find the best place for the overview. The finished documentation should explain a minimal proxying setup, show how Gateways, Providers, and Models relate with a Mermaid diagram, and include an appendix on adding policies.