Update Breadcrumb API

[Littletonconnor]

Overview

Fixes #19 by exposing BreadcrumbLink since React aria's Link component no longer clones children.

Example

• There's no longer duplicate anchor elements.

Docs

• I tried to keep the docs light and just point to the React aria component docs instead. I wasn't sure where the best place to put this was but I tried to also follow other conventions I saw used on different components like Input

[IHIutch]

This is great, thank you!