Add optic for documentation

[ukmadlz]

Solution for #355

Thanks for making a really awesome rest boilerplate, I really appreciate how useful it is to have a drag and drop starter for new APIs and apps.

I've added Optic as an alternative to apiDoc, as the middleware is non-intrusive and it allows you to capture the API endpoints as you develop the app (including changes). You can then use api generate:oas to get an OpenAPI as part of the process. I've gone ahead and added the middleware and the pointers in the README, I've set it to only run in non-production setups with minimal hassle and to not get in the way of the users flow if they don't want to use the tooling.