Add swagger documentation for API

[dipeshdulal]

Swagger Documentation for clean-gin

[Fimeo]

In order to continue the template with a swagger documentation. I propose to use an OpenApi v3 interface contract in json format in an api folder: swagger.json.

Moreover, it could be interesting to add a schema validator like https://github.com/getkin/kin-openapi on the requests made on the server through the creation of a middleware.

[dipeshdulal]

@Fimeo
Thank you. Didn't know about kin-openapi project.
Looks interesting and useful.

So, kin-openapi can validate request inputs and response output from the openapi schema as well or just validate schema only? 🤔

[Fimeo]

Yes kin openapi takes the request and validates all schema against the openapi definition. It was really usefull for standard validation and provides low code and easy validation. You can validate the input request and if an error was found, cancel the request with appropriate error message.

[dipeshdulal]

Wow. 🤩
This really looks useful.
I will try to integrate with our architecture soon. 🏃 💨