feat: Descriptions in generated api spec

[Anders-eide-stacc]

I am currently converting a backend service from tsoa to typoa (due to type errors in the generated spec), but one feature I am currently missing in typoa is that tsoa would embed JSdoc comments from each controller endpoint into the generated api spec.

Would it be possible to implement some way of adding descriptions into the generated api spec in typoa too? It wouldn't have to be as fancy as tsoa, for my use case it would be perfectly acceptable to have a @Description-decorator for example that just takes a plain string which would be used as the endpoint description.

Perhaps also add a description-property to the openapi.service-object that the generate function takes as well, that could serve as the service description in the generated spec.

Love the work on this library overall. ❤️