Add support for deprecated fields

[detomarco]

Is your feature request related to a problem? Please describe.
I deprecated a field in Kotlin, I'd like to have the deprecated annotation in the schema

• A clear and concise description of what the problem is. Ex. I'm always frustrated
  when [...]

I defined this data class in Kotlin

data class Car(
     @Deprecated
     val model: String
)

• What is the actual result using OpenAPI Description (yml or json)?

components:
  schemas:
    Car:
      required:
      - brand
      type: object
      properties:
        brand:
          type: string

Describe the solution you'd like

components:
  schemas:
    Car:
      required:
      - brand
      type: object
      properties:
        brand:
          deprecated: true
          type: string