Fix typo: change 'Explictly' to 'Explicitly'

Author: joaolago1113

book/src/help_bn.md

@@ -26,7 +26,7 @@ FLAGS:
                                                contention which degrades staking performance. Stakers should generally
                                                choose to avoid this flag since backfill sync is not required for
                                                staking.
-        --disable-deposit-contract-sync        Explictly disables syncing of deposit logs from the execution node. This
+        --disable-deposit-contract-sync        Explicitly disables syncing of deposit logs from the execution node. This
                                                overrides any previous option that depends on it. Useful if you intend to
                                                run a non-validating beacon node.
     -x, --disable-enr-auto-update              Discovery automatically updates the nodes local ENR with an external IP
@@ -511,4 +511,4 @@ OPTIONS:
             Specify a weak subjectivity checkpoint in `block_root:epoch` format to verify the node's sync against. The
             block root should be 0x-prefixed. Note that this flag is for verification only, to perform a checkpoint sync
             from a recent state use --checkpoint-sync-url.
-```
+```