update json-schema template to new structure

[mashehu]

First try at #687
Not sure if we really need to ditch type:objectfor groups as done in the example, because they still contain properties. This would also mean less changes in the other code (which often identifies a group by type==object). But maybe I misunderstood the changes for the new structure. 🤷‍♂️

[ewels]

Note to self: diff is mostly whitespace, see diff without whitespace

I don't quite understand your comment - you have ditched the type:object in this PR, right? The definitions entries can still have their own properties..

[mashehu]

no, all elements except for parameters are still all type:object as before, including the topmost element with the definitions. The latter was in the example you posted, so I left it like that.

[ewels]

Yeah, I think that the topmost element needs to be an object. I hadn't noticed that the type:object lines were still there in this PR. I think you can just delete them..?

Maybe I should back up and give a proper explanation for why the nasty hack was needed. I'll add a comment with this to #687

[ewels]

I was wrong: #687 (comment)

Good to merge ✅ - will do so into a branch so as not to mess up dev until we're ready.

Will start working on updating the rest of the code and fixing the tests.