Reason for HTTP Return Code 400 is not fully described in openapi

[dh3wr]

Describe the bug

https://github.com/corona-warn-app/cwa-quicktest-onboarding/blob/master/api/quicktest-openapi.json states

"responses": {
  "204": {
    "description": "Content created"
  },
  "400": {
    "description": "Client Certificate not accepted" 
  }
}

That's just half of the truth. If you have a json object format error, you will also get 400, although your client cert. is corret.

Expected behaviour

Update docs to reflect, that 400 is not only caused by Client Certificate not accepted, but can have other reasons, too.

Steps to reproduce the issue

Just forget to make an array for the rest result, you'll get 400.

Possible Fix

Update docs

Additional context