Update JSON Schema to directly take Encodable Object

[rudrankriyam]

Update OpenAIChatCompletionRequestBody to directly take encodable schema. This helps with Generable in foundation models framework

[lzell]

Very cool, would love to see a snippet of you using this with Generable!

[rudrankriyam]

Should update the README somewhere in another PR; what do you think

[lzell]

Yes that would def be helpful. I'm also wondering if we should go with the name generableJSONSchema. Because just putting any old encodable in there is going to lead to wonky results

[lzell]

(since it needs to conform to https://json-schema.org/overview/what-is-jsonschema)

[rudrankriyam]

Agreed

[lzell]

I'm going to rename on main right now