Update withdrawl flow

[bradleycamacho]

Description

https://docs.optimism.io/stack/transactions/withdrawal-flow

Simplify naming, needs to be updated with the latest version of the stack and viem.

Action items

1. Do research on topic and raise any questions with the docs team
2. Write a first draft. It doesn't have to be worded perfectly as the docs team will review
3. Ping @bradleycamacho on discord and request review
4. Implement feedback from @bradleycamacho
5. Publish