Feature/add choice tree form type

[Charlie-Lucas]

No description provided.

[merk]

Thanks for your work on this, it looks like it might come in handy for some people.

Is there a particular reason you want to submit it here instead of maintaining your own bundle? I don't think we'd be able to support this form type because we wont be using it internally.

[Charlie-Lucas]

In the development of our private projects or not, we need to create some new types of forms , we would regroup all these types of forms in an open-source bundle, and we thought it was best idea to add this functionality to an existing project rather than creating our own.
Maybe i can create a demo bundle to support this form type and understand how it work.