Create openapi spec based on mongoose schema

[abelhbeyene]

Create an endpoint which shows an OpenApi spec for all the endpoints. The actual spec can be created using mongoose-to-swagger.

This can be automated so that as we iterate on the Models the doc is automatically updated.

This is assuming that the Models are a representation of the data they expose through one of the handlers.

@naody - thoughts?

Example implementation:

// In a handler
const swaggerSpecs = Object.keys(Models).map((model) => {
    return m2s(Models[model])
 })
handleResponse(callback, swaggerSpecs)