Expose OpenAPI spec if one exists

[zackdotcomputer]

Hey! Looking to build on top of this API and it would be really helpful if there were an OpenAPI spec or equivalent available for it. I'm guessing from the way the docs are laid out that these are at least partially codegen'd by some tool.

If that tool is ingesting a markup definition of the API, could the markup version be exposed?

If the markup is exposed already, could you point me to it and I'll create a PR to add links to it from the site and Readme?

If that tool is reading the source code, can it be configured to generate an OpenAPI spec in addition?

My main motivation here is that specs like OpenAPI can be used to:

1. Easily mock the servers so I don't mess up my production LunchMoney account
2. Set up Postman so I can make manual API calls and inspect the results
3. Automatically generate API clients in different languages