Is queuing on the worker "processing"?

**What happened**:

Could I clarify a description in the [documentation](https://distributed.dask.org/en/latest/scheduling-state.html)?

It states:

> Processing: Actively being computed by one or more workers

And also:

> Multiple tasks may be submitted to a worker in advance and the worker will run them eventually, depending on its execution resources (but see Work Stealing).
All the tasks here are in the “processing” state.

Does this mean that a worker has a queue and all tasks in the queue are "processing", even if they're not being computed?

**What you expected to happen**:

Happy to PR a change to the first definition to something like "Either actively being computed by one or more workers or in a worker queue" if that's more representative.