f add more details on ConfirmationTarget

Author: TheBlueMatt

CHANGELOG.md

@@ -8,7 +8,8 @@
  * `ConfirmationTarget` has been rewritten to provide information about the
    specific use LDK needs the feerate estimate for, rather than the generic
    low-, medium-, and high-priority estimates. This allows LDK users to more
-   accurately target their feerate estimates (#2660).
+   accurately target their feerate estimates (#2660). For those wishint to
+   retain their existing behavior, see the table below for conversion.
  * `ChainHash` is now used in place of `BlockHash` where it represents the
    genesis block (#2662).
  * `lightning-invoice` payment utilities now take a `Deref` to
@@ -18,6 +19,16 @@
  * `Display` is now implemented for `Outpoint` (#2649).
  * `Features::from_be_bytes` is now provided (#2640).
 
+For those moving to the new `ConfirmationTarget`, the new variants in terms of
+the old mempool/low/medium/high priorities are as follows:
+ * OnChainSweep = HighPriority
+ * MaxAllowedNonAnchorChannelRemoteFee = max(25 * 250, HighPriority * 10)
+ * MinAllowedAnchorChannelRemoteFee = MempoolMinimum
+ * MinAllowedNonAnchorChannelRemoteFee = Background - 250
+ * AnchorChannelFee = Background
+ * NonAnchorChannelFee = Normal
+ * ChannelCloseMinimum = Background
+
 ## Bug Fixes
  * Calling `ChannelManager::close_channel[_with_feerate_and_script]` on a
    channel which did not exist would immediately hang holding several key