message: docs(core): improve TransactionInfo docs
  Issue:
diff: @@ -94,6 +94,7 @@ export interface TransactionExplanation extends BaseTransactionExplanation<strin
  }
  export interface TransactionInfo {
  + /** Maps txid to txhex. Required for offline signing. */
  txHexes?: Record<string, string>;
  changeAddresses?: string[];
  unspents: Unspent[];
  