text: Title: Swagger issue for endpoints register & update
  Body: Hi, 
  First of all, great job. It's a very useful library.
  
  However, after having setup my project. I noticed a few issues in the generated Swagger documentation. Indeed, the request body is pre-filled with the following information:
  ```
  {
    "id": "string",
    "email": "user@example.com",
    "is_active": true,
    "is_superuser": false,
    "password": "string"
  }
  ```
  
  However, according to your documentation, only the fields `email` & `password` are required. It can lead to some misunderstandings for someone wanting to use the API for the first time since the Swagger (or redoc) should describe how to use the API.
  
  I think it's a cheap fix that can be very useful for when you'll find a solution for adding auth in the Swagger. Indeed, after having had a look at your code, one solution could be to make the models `BaseUserCreate` and `BaseUserUpdate` not to inherit from `BaseUser` but `BaseModel` instead.
  
  Looking forward to hearing from you :)
  