Note about a DedicatedWorkerGlobalScope's owner set seems under-explained

[kenchris]

According to HTML you can create a dedicated worker inside a shared worker, thus, the owner

So yes, a ADedicatedWorkerGlobalScope's owner set will always have exactly one item, as the note states, but that owner might be a SharedWorkerGlobalScope that can have an owner set of multiple documents.

The algorithm for owning document will in that case return null: https://wicg.github.io/page-lifecycle/#worklets-workers

If that is the intention, I think the note should explain that better.