config: update batch inbox address convention to support 256 bit chai…

…n IDs (#249)

.markdownlint.json

@@ -10,5 +10,6 @@
   "no-empty-links": false,
   "single-title": false,
   "no-emphasis-as-heading": false,
-  "no-duplicate-header": false
+  "no-duplicate-header": false,
+  "no-inline-html": false
 }

specs/protocol/configurability.md

@@ -39,7 +39,7 @@ These requirements are currently a draft, pending governance approval.
 
 | Config Property                       | Description                                                                                                                  | Administrator                       | Standard Config Requirement | Notes |
 |---------------------------------------|------------------------------------------------------------------------------------------------------------------------------|-------------------------------------|-------------------------------------|-------------------------------------|
-| [Batch Inbox address](https://github.com/ethereum-optimism/optimism/blob/c927ed9e8af501fd330349607a2b09a876a9a1fb/packages/contracts-bedrock/src/L1/SystemConfig.sol#L176)                   | L1 address where calldata/blobs are posted (see [Batcher Transaction](../glossary.md#batcher-transaction)).                  | Static | Current convention is `0xff000...000{chainId}`. | Follow convention if possible. A future hardfork plans to migrate Batch Inbox Addresses to better support `uint256` sized chain IDs. |
+| [Batch Inbox address](https://github.com/ethereum-optimism/optimism/blob/c927ed9e8af501fd330349607a2b09a876a9a1fb/packages/contracts-bedrock/src/L1/SystemConfig.sol#L176)                   | L1 address where calldata/blobs are posted (see [Batcher Transaction](../glossary.md#batcher-transaction)).                  | Static | Current convention is <code>versionByte &vert;&vert; keccak256(bytes32(chainId))[:19]</code>, where <code>&vert;&vert;</code> denotes concatenation, `versionByte` is `0x00`, and `chainId` is a `uint256`. | It is recommended, but not required, to follow this convention. |
 | [Batcher Hash](./system_config.md#batcherhash-bytes32) | A versioned hash of the current authorized batcher sender(s). | [System Config Owner](#admin-roles) | `bytes32(uint256(uint160(batchSubmitterAddress)))` | [Batch Submitter](../protocol/batcher.md) address padded with zeros to fit 32 bytes. |
 | [Chain ID](https://github.com/ethereum-optimism/superchain-registry/blob/main/superchain/configs/chainids.json)                              | Unique ID of Chain used for TX signature validation.                                                                         | Static | Foundation-approved, globally unique value [^chain-id]. | Foundation will ensure chains are responsible with their chain IDs until there's a governance process in place. |
 | [Challenge Period](../protocol/withdrawals.md#withdrawal-flow)                      | Length of time for which an output root can be removed, and for which it is not considered finalized.                        | [L1 Proxy Admin](#admin-roles)                      | 7 days | High security. Excessively safe upper bound that leaves enough time to consider social layer solutions to a hack if necessary. Allows enough time for other network participants to challenge the integrity of the corresponding output root. |