add jsonSchema metadata property

[ssalbdivad]

this would allow a type to be associated with arbitrary JSON schema that would be returned when calling toJsonSchema (or through Standard JSON Schema)

[yamcodes]

I can take this if you want to assign me. Correct me if I'm wrong but this looks like a good first "code" type issue, right?

[ssalbdivad]

absolutely- go for it! I would take a look at NodeMeta in ark/schema/shared/declare.ts, which you could add this jsonSchema property to. I guess there are some footguns here, e.g. configure normally applies the config to all shallow nodes, but that would rarely be desirable for JSON Schema as it would lead to misleading results for nested nodes (although those would probably never be seen in the vast majority of cases).

Also whether jsonSchema should accept some kind of function that would map the inner node to its jsonSchema value so it could be more general? I suppose we could support this in the future and just do the basic version now where the JSON schema provided has to be an actual value.