OpenAPI support for Node projects

While we've supported OpenAPI and Swagger from the start for Django projects, we didn't have this support for Node projects immediately.

I'm happy to announce that with our latest update last week, we now fully support OpenAPI 3.0 and live Swagger UI in the Node projects you generate with API Bakery!

The support is not enabled by default as some developers might not need it. To enable it, just mark the "OpenAPI" checkbox when configuring your project.

Since we're already using json-schema for request body validation, we include the object model schemas for OpenAPI, keeping a single source of truth for API. We also rely on swagger-jsdoc to document the API endpoints themselves, and use swagger-ui-express to provide a live UI and documentation using Swagger.