Port changes into Alchemy CMS

[alexanderadam]

It would be nice to have this functionality directly in Alchemy CMS and the maintainer would love to see this as well as it seems:

[mtomov]

I think the goal would be to be able to define the model fields using the same semantics as elements.yml, so that we can have all sorts of different fields - select, file and image picker, etc?

It's like having an alchemy element be a model