Intent-to-implement: TypeScript definitions

I've seen a couple of people asking whether there are any TS definitions available for HIG components. The Rosewood scrum team have been working on `.d.ts` files for HIG components as part of our current project. We have an incomplete set of definitions which we'd like to contribute as a starting point.

Start by reviewing the incomplete .d.ts files for HIG components mentioned in the issue and comparing them with the corresponding HIG component APIs. Done means contributing the available TypeScript definitions as a usable starting point, but the issue does not specify the files, test command, or completeness criteria.

Written by the indexing model from the issue text.