Improve Cloudflare version metadata documentation

@david said:

> another cloudflare thing we should improve: [https://developers.cloudflare.com/workers/runtime-apis/bindings/version-metadata/](https://developers.cloudflare.com/workers/runtime-apis/bindings/version-metadata/)
>
> [Version metadata](https://developers.cloudflare.com/workers/runtime-apis/bindings/version-metadata/)