Allow task list to be specified via preset? If not, document.

[benjie]

Feature description

https://worker.graphile.org/docs/config#worker-options doesn't indicate a task list. If this is deliberate, document why it's not there. If it's not deliberate, consider adding it.

Motivating example

https://discordapp.com/channels/489127045289476126/697954986461495346/1211476431113027705

Breaking changes

None

Supporting development

I [tick all that apply]:

• am Benjie