Fix: engine nits

[julio4]

This PR fixes a few nits I've found while reviewing specs.

[MysticRyuujin]

Good fixes overall, but two issues to address:

1. Wrong anchor for verify_cell_kzg_proof_batch

The PR changes the anchor from #verify_cell_kzg_proof_batch to #verify_cell_kzg_proof_batch_impl, but the spec text is calling the public function — _impl is the internal implementation. The anchor
should stay as #verify_cell_kzg_proof_batch.

2. Grammar in engine_getPayloadV5 description

it returns as BlobsBundleV2

Should be:

it returns BlobsBundleV2

---

Everything else looks correct:

• BlobBundleV1 → BlobsBundleV1 typo fix ✅
• SECONDS_PER_SLOT → SLOT_DURATION_MS is accurate (upstream renamed it, dev branch is 404) ✅
• #beaconblocksbyroot-v1 and #beaconblocksbyrange-v1 anchors both exist on master ✅
• #executionpayload anchor is valid on master ✅

[julio4]

Good fixes overall, but two issues to address:

1. Wrong anchor for verify_cell_kzg_proof_batch

The PR changes the anchor from #verify_cell_kzg_proof_batch to #verify_cell_kzg_proof_batch_impl, but the spec text is calling the public function — _impl is the internal implementation. The anchor should stay as #verify_cell_kzg_proof_batch.

2. Grammar in engine_getPayloadV5 description

it returns as BlobsBundleV2

Should be:

it returns BlobsBundleV2

Good find thanks. Fixed

[MysticRyuujin]

@mkalinin think you could review this one?

[mkalinin]

I think it would be more stable to have a link anchored to a specific commit. wdyt?

[julio4]

I guess it's a choice to make. My intuition is that the specs should not change drastically and master branch is considered the latest stable version.