Type definitions for browser version of the sdk

**Before you start**
Have you checked StackOverflow, previous issues, and Dropbox Developer Forums for help? Yes

**What is your question?**
I'm struggling to find any type definitions for the browser environment version of the sdk. The type definitions available in the repo and on npm appear to be relevant strictly for the node env.

Is it possible to get / generated type definitions files for the browser environment?

**Versions**
* What version of the SDK are you using? Latest
* What version of the language are you using? ES6+
* Are you using Javascript or Typescript? Typescript
* What platform are you using? (if applicable) Chrome

**Additional context**
None