add some comments and formatting

specs/_features/eip7251/beacon-chain.md

@@ -624,6 +624,9 @@ def process_epoch(state: BeaconState) -> None:
 
 #### Updated  `process_registry_updates`
 
+`process_registry_updates` uses the updated definition of `initiate_validator_exit`
+and changes how the activation epochs are computed for eligible validators.
+
 ```python
 def process_registry_updates(state: BeaconState) -> None:
     # Process activation eligibility and ejections
@@ -693,6 +696,8 @@ def process_pending_consolidations(state: BeaconState) -> None:
 
 #### Updated `process_effective_balance_updates`
 
+`process_effective_balance_updates` is updated with a new limit for the maximum effective balance.
+
 ```python
 def process_effective_balance_updates(state: BeaconState) -> None:
     # Update effective balances with hysteresis
@@ -834,14 +839,16 @@ def process_operations(state: BeaconState, body: BeaconBlockBody) -> None:
     for_ops(body.deposits, process_deposit)  # [Modified in EIP7251]
     for_ops(body.voluntary_exits, process_voluntary_exit)  # [Modified in EIP7251]
     for_ops(body.bls_to_execution_changes, process_bls_to_execution_change)
-    for_ops(body.execution_payload.withdraw_requests, process_execution_layer_withdraw_request)  # New in EIP7251
-    for_ops(body.consolidations, process_consolidation)  # New in EIP7251
+    for_ops(body.execution_payload.withdraw_requests, process_execution_layer_withdraw_request)  # [New in EIP7251]
+    for_ops(body.consolidations, process_consolidation)  # [New in EIP7251]
 ```
 
 ##### Deposits
 
 ###### Updated  `apply_deposit`
 
+*NOTE*: `process_deposit` is updated with a new definition of `apply_deposit`.
+
 ```python
 def apply_deposit(state: BeaconState,
                   pubkey: BLSPubkey,
@@ -1044,7 +1051,7 @@ def process_voluntary_exit(state: BeaconState, signed_voluntary_exit: SignedVolu
     assert get_current_epoch(state) >= voluntary_exit.epoch
     # Verify the validator has been active long enough
     assert get_current_epoch(state) >= validator.activation_epoch + SHARD_COMMITTEE_PERIOD
-    # Only exit validator if it has no pending withdrawals in the queue
+    # [New in EIP-7251] Only exit validator if it has no pending withdrawals in the queue
     assert get_pending_balance_to_withdraw(state, voluntary_exit.validator_index) == 0  # [New in EIP7251]
     # Verify signature
     domain = compute_domain(DOMAIN_VOLUNTARY_EXIT, CAPELLA_FORK_VERSION, state.genesis_validators_root)