API rules

[rbarrois]

Describe the API (including Sphinx doc):

• How do we return errors, including human-readable messages?
• How do we return a paginated list of items?
• How do we return a single item?
• What should be the response to an object creation/modification request?

[rbarrois]

Idea:

{
  "errors": [
    {
      "code": "invalid_field",
      "field": "address_city",
      "message": "La ville « PParis » est inconnue"
    }
  ]
}