Missing platforms prop in StyleDictionary.Core types

[jorenbroekema]

Hey, perhaps I'm mistaken about this but I believe there's a missing property in StyleDictionary.Core type (index.d.ts)

I believe https://github.com/amzn/style-dictionary/blob/main/types/index.d.ts#L72 should contain a line:

platforms: Platform[];

Let me know if that's correct, right now in TypeScript I'm creating a StyleDictionary instance with sd.extend(...) and it says it doesn't have a platforms property, even though I am pretty sure that it does :)