Ability to set a dynamic language on the code field

[paulpopus]

Currently the language used for the editor and therefore syntax highlighting has to be set inside the config which kind of limits your experience as you can't always predict what kind of code you're going to add to it.

A nice solution might be to allow the language admin config to take a function with doc or siblingData to be passed into it so the developer can hook their own language field.

Alternatively, this additional field is built-in and then the value of it is passed as a prop to the code.