Document that @JsonUnwrapped also applies to deserialization

[mjustin]

The Stack Overflow question What's the Jackson deserialization equivalent of @JsonUnwrapped? currently has 52 upvotes. It is therefore clear that users are surprised to find that @JsonUnwrapped also applies to deserialization.

A prime source of this confusion appears to be the fact that the documentation for @JsonUnwrapped does not mention deserialization at all:

Annotation used to indicate that a property should be serialized "unwrapped"

Other annotations that apply to both serialization & deserialization call this out in the documentation, including @JsonIgnoreProperties, @JsonIgnoreProperties, & @JsonView.

It seems therefore that it would be helpful if the Javadocs mentioned that the annotation applies to deserialization as well as serialization.

[cowtowncoder]

Sounds reasonable: if anyone has time, PR (against branch 2.12, I think) would be very welcome.
Unfortunately javadocs mostly get updated when code changes, but in case of annotations code mostly changes in jackson-databind and annotations themselves are not modified, just their applicability.