Custom batch inbox address is not documented

[antonio-altr]

Normally the batch inbox address (such as in Sepolia) is set as:

optimism/packages/contracts-bedrock/deploy-config/getting-started.json

Line 19 in 006f891

"batchInboxAddress": "0xff00000000000000000000000000000000042069",

However, there is some re-routing done to make the DA aspect work, and the true batch inbox address is now:

optimism/op-service/txmgr/txmgr.go

Line 225 in 46d8e6a

if candidate.To.Hex() == "0xfF00000000000000000000000000000000000000" {

This change is not documented in the deployment guide: https://github.com/celestiaorg/optimism/blob/celestia-develop/docs/op-stack/src/docs/build/getting-started.md

There are actually 2 places to make this substitution:

1. First, before the "Deploy the L1 contracts" step, we must change the address inside getting-started.json
2. Second, after the "Generate the L2 config files" step, we must change the address inside rollup.json