docs: add to release notes

Author: bitromortac

docs/release-notes/release-notes-0.18.3.md

@@ -84,6 +84,9 @@
 * [`ChanInfoRequest`](https://github.com/lightningnetwork/lnd/pull/8813)
   adds support for channel points.
 
+* [BuildRoute](https://github.com/lightningnetwork/lnd/pull/8886) now supports
+  inbound fees.
+
 ## lncli Updates
 
 * [`importmc`](https://github.com/lightningnetwork/lnd/pull/8779) now accepts