Document worker costs

Erwan Rouchet
2025-04-01T14:10:37Z

Under the existing [advanced worker documentation](https://doc.arkindex.org/workers/advanced/), a new **Costs** section should introduce costs and explain that they are only used to give hints to users and do not affect running processes...

Under the existing advanced worker documentation, a new Costs section should introduce costs and explain that they are only used to give hints to users and do not affect running processes, and describe the three available costs and their meaning.