OpenAPI server/client generation function

[Rz-Rz]

Is your feature request related to a problem? Please describe.
It would be great to be able to use the OpenAPI format to describe endpoint and vice versa having the possibility to generate the client. It allows easy visualization of the different endpoints that a Drogon server can offer, enhancing productivity across teams.

Describe the solution you'd like
An OpenAPI generator for the server and the client.

Describe alternatives you've considered
Manually describing an already built Drogon app using YAML and OpenAPI syntax. But it is tedious work, that could be automatized.

Additional context
Any Swagger API yaml visualization.