[Durable Objects] Include RPC as an alternative to `fetch`ing a stub

[KianNH]

Existing documentation URL(s)

• https://developers.cloudflare.com/durable-objects/best-practices/access-durable-objects-from-a-worker/#3-use-fetch-handler-method

What changes are you suggesting?

It'd be good to showcase RPC here, since fetching a Durable Object class instance is sometimes confusing for new users.

Additional information

No response

[KianNH]

Maybe step 3 could be removed and instead point to https://developers.cloudflare.com/durable-objects/best-practices/create-durable-object-stubs-and-send-requests/#call-a-durable-object which already covers RPC and fetch()

[KimJ15]

This issue is pretty stale. Closing as won't do for now.