fhir-4: In docs, pull out common properties form the builders

[josephjclark]

At the moment fhir-4 generates quite noisy documentation:

Of the properties in this object, quite a few of them are repeated verbatim for every builder (and there's like 300 builders or something crazy).

We could reduce bloat by calculating any properties that are present on all builders - and we can calculate this - and creating a typedef for them. So we say like "This builder supports the common properties in Resource, plus the following".

I do not want to generate a typedef per builder. It'll just be super messy in the docs. I waat those types inline.

At a quick guess we could abstract out id, meta, text, language, implicitRules and extension. Even just taking out that list would make a significant difference to the size of the page.

Then we could say: for any type which has a different description (or schema generally), go ahead and add an override to the types table. But I don't think that will happen much.

Also, just because something isn't in the docs, doesn't mean it can't be set. We don't have to document implicitRules but you can still set it on the builder and it'll be accepted just fine.

[josephjclark]

I really like the idea of this hard-coded list - it'll make a huge difference