fix: add notes about the new max_weight_to_satisfy

crates/bdk/src/wallet/tx_builder.rs

@@ -336,10 +336,12 @@ impl<'a, D, Cs: CoinSelectionAlgorithm, Ctx: TxBuilderContext> TxBuilder<'a, D,
  /// causing you to pay a fee that is too high. The party who is broadcasting the transaction can
  /// of course check the real input weight matches the expected weight prior to broadcasting.
  ///
- /// TODO: add notes about the new `max_weight_to_satisfy`
  /// To guarantee the `max_weight_to_satisfy` is correct, you can require the party providing the
  /// `psbt_input` provide a miniscript descriptor for the input so you can check it against the
  /// `script_pubkey` and then ask it for the [`max_weight_to_satisfy`].
+ /// Be aware that `max_weight_to_satisfy` uses `segwit_weight` instead of `legacy_weight`,
+ /// if you want to include only legacy inputs in your transaction, you should remove 1WU
+ /// from each input's `max_weight_to_satisfy` for a more accurate estimate.
  ///
  /// This is an **EXPERIMENTAL** feature, API and other major changes are expected.
  ///