Improve 'Confirmed Transactions' section

Author: tnull

docs/blockchain_data/confirmed_transactions.md

@@ -4,20 +4,29 @@ Up until this point, we've explored how to notify LDK of chain activity using
 blocks. But what if you're sourcing chain activity from a place that doesn't
 provide a block-centric interface, like Electrum?
 
-LDK has a `chain::Confirm` interface to support this use case, analogous to the
-block-oriented `chain::Listen` interface which we've been using up until now.
-With this alternative approach, you still need to give LDK block headers, but
-only for blocks containing transactions of interest. These are identified by
-`chain::Filter` as before. You also need to notify LDK of any transactions with
-insufficient confirmation that have been reorganized out of the chain. Use the
+LDK's `ChannelManager` and `ChainMonitor` have a `chain::Confirm` interface to
+support this use case, analogous to the block-oriented `chain::Listen`
+interface which we've been using up until now. With this alternative approach,
+you still need to give LDK information about chain activity, but only for
+transactions of interest. These are identified by
+`Confirm::get_relevant_txids`, as well as by `Filter`'s
+`register_tx`/`register_output` methods, just as before.
+
+You also need to notify LDK of any transactions with insufficient confirmations
+that have been reorganized out of the chain. Use `Confirm`'s
 `transactions_confirmed` and `transaction_unconfirmed` methods, respectively.
 
 Additionally, you must notify LDK whenever a new chain tip is available using
-the `best_block_updated` method. See the documentation for a full picture of how
-this interface is intended to be used.
+the `Confirm::best_block_updated` method. See the documentation for a full
+picture of how this interface is intended to be used.
+
+::: tip Note 
+Note that the described methods of `Confirm` have to be called both on the
+`ChannelManager` *and* the `ChainMonitor`.
+:::
 
 ::: tip Note
 Be advised that `chain::Confirm` is a less mature interface than
-`chain::Listen`. As such, there is not yet a utility like `lightning-block-sync`
-to use for interacting with clients like Electrum.
+`chain::Listen`. As such, there is not yet a utility like
+`lightning-block-sync` to use for interacting with clients like Electrum.
 :::