[ty] Add a go-to destination for `Divergent` (#26162)
## Summary
`Divergent` is here to stay, and we've documented what it means:
https://github.com/astral-sh/ty/commit/d299a29cc182e9ade2ef9f96e2002acbc209aee8.
This PR adds a go-to target for the type, so that users can
command+click on the type when it appears in inlay hints in VSCode, and
they'll be taken to a definition that has documentation explaining the
type's meaning.
## Test Plan
Hovering over an inlay hint in a local deploy of the playground:
<details>
<summary>Screenshot</summary>
<img width="1678" height="942" alt="image"
src="https://github.com/user-attachments/assets/a4061e24-145d-4bfd-ba82-d7c9b9ba4c1f"
/>
</details>
