missing details for multi-worker DO script_name settings

### Existing documentation URL(s)

- https://developers.cloudflare.com/workers/testing/miniflare/core/multiple-workers
- https://developers.cloudflare.com/workers/testing/miniflare/storage/durable-objects

### What changes are you suggesting?

This section: https://developers.cloudflare.com/workers/testing/miniflare/core/multiple-workers/#durable-objects

Points to for more details (within the context of multi-worker and `script_name`): https://developers.cloudflare.com/workers/testing/miniflare/storage/durable-objects/#using-a-class-exported-by-another-script

The latter link however redirects to first one, practically looping back.

We should fix this incorrect loop and potentially offer more details/an example on how to use `script_name`.

It does seem like this information was present in the old miniflare md docs but was never ported to the Cloudflare docs: https://github.com/cloudflare/miniflare/blob/master/docs/src/content/storage/durable-objects.md#using-a-class-exported-by-another-script

### Additional information

_No response_