DOC: improve formatting

[KES777]

On the page

required keyword is not aligned properly and makes confusion a bit.

It would be more clear if you move this keyword after type and before properties

[darrelmiller]

Thanks for spotting this. Would there be any chance you could create a PR to fix it against the 3.0.2-dev branch?

[MikeRalphson]

It would be nice to have the required array positioned consistently with regard to the type and properties properties in all the examples. Personally I prefer it to follow properties, as then the required array isn't seen as referencing properties which haven't been introduced yet, but of course the notion of property ordering in JSON/JSON-schema is artificial.

[webron]

Fixed by #2132.