Deprecated fields

[liamg]

Is your feature request related to a problem? Please describe.
I want to mark a field of one of my API models as deprecated, for future removal.

Something like:

type MyModel struct {
  A string `json:"a"`
  B string `json:"b"`
  C string `json:"c" deprecated:"Please use 'MyModel.other' instead"`
  Other string `json:"other"`
} // @MyModel

Describe the solution you'd like
See above! A way of getting the field swagger deprecated parameter set to true, and ideally some kind of deprecation message stored somewhere - perhaps on the field description?

Describe alternatives you've considered
Adding a custom message to the field description, but this doesn't set the deprecated field property.

Additional context
n/a

Happy to PR this in if it's a desirable feature!

[sdghchj]

PR welcome