Add option to Jet CLI to generate models with JSON struct tags

[IcyFoxe]

I tried to figure out how to generate code with JSON struct tags, but all solutions lead to this link at https://github.com/go-jet/jet/wiki/Generator#generator-customization, which as far as I understand means you need to generate from code instead from prebuilt CLI, and you need to implement it yourself, which is not an easy task for someone who's just starting out with this package.

It would be nice if there was a simple option in Jet CLI that would add these JSON struct tags to the models automatically. For example -json-tags=true.

[go-jet]

Agree, makes sense to add a new cli option. Something like: -model-json-tag with possible values none, camel-case, pascal-case or snake-case.