CL-EL withdrawals harmonization: using units of Gwei (#354)

src/engine/shanghai.md

@@ -37,9 +37,10 @@ The fields are encoded as follows:
 - `index`: `QUANTITY`, 64 Bits
 - `validatorIndex`: `QUANTITY`, 64 Bits
 - `address`: `DATA`, 20 Bytes
-- `amount`: `QUANTITY`, 256 Bits
+- `amount`: `QUANTITY`, 64 Bits
 
-*Note*: the `amount` value is represented on the beacon chain as a little-endian value in units of Gwei, whereas the `amount` in this structure *MUST* be converted to a big-endian value in units of Wei.
+*Note*: the `amount` value is represented on the beacon chain as a little-endian value in units of Gwei, whereas the
+`amount` in this structure *MUST* be converted to a big-endian value in units of Gwei.
 
 ### ExecutionPayloadV2
 
@@ -142,4 +143,4 @@ This method follows the same specification as [`engine_forkchoiceUpdatedV1`](./p
 
 This method follows the same specification as [`engine_getPayloadV1`](./paris.md#engine_getpayloadv1) with the addition of the following:
 
-  1. Client software **SHOULD** use the sum of the block's priority fees or any other algorithm to determine `blockValue`.
+  1. Client software **SHOULD** use the sum of the block's priority fees or any other algorithm to determine `blockValue`.