Add example using struct for RangeDeserialize

[rminderhoud]

The RangeDeserialize and RangeDeserializeBuilder functionality is great but it's not immediately clear that these functions are closely integrated with serde. All the examples show the values being deserialized into a tuple but I think it would be good to have at least one example somewhere showing how it can be deserialized into a struct in combination with serde.

[tafia]

You're right! Happy to merge any PR, else I'll probably do it next week.

[dennismarwood]

Any chance you could provide a quick example in this issue until you have time to get it added to the documentation? Or let me know if it is necessary to implement https://serde.rs/deserialize-struct.html if we want to iterate over the rangeDeserializer into a custom struct?