API Documentation

[georg-schwarz]

On branch wahlzeit-40-new-ui.

We should document the backend API in an interactive way. I suggest to use swagger to generate an OpenApi spec that we can feed into a Swagger-UI container.

[Juliiia]

After we discussed that the wahlzeit-40-new-ui branch is not working, I created a branch (swagger_integration) for swagger integration based on the master branch. Based on the current state a gradle task automatically creates a yaml that includes the API documentation. Currently, a basic yaml will be created. To document the API methods annotations need to be added.