Move To A Better Format

[PeterHindes]

From my peruasl of this repository it seems like the whole documentation is in source/index.html.md which seems like bad form. I propose using the industry standard OpenAPI language: https://www.openapis.org/

In the future this will make it easier to generate tests and ensure our interface remains consistent. This will ultimately allow future frontend rewrites to be done with much more confidence.

I am currently exploring using an llm to translate the current markdown into openapi and will have more to report soon.

For examples of what openapi can do: see this example file and its result from redoc