Add custom operation

[gquittet]

Hello guys,

I need to add a feature in json-logic-rs to let the user defines a custom operator.

See: https://jsonlogic.com/add_operation.html

PyO3 makes this feature possible: https://pyo3.rs/

However, json-logic-rs uses CPython and I don't find any resource on that.

Are you OK with this feature and what do you think about helping me to integrate that into the code base as I'm new in the project.

I already tested the func.rs and it's not working and can't meet my need.