docs: release notes update for 0.18.0

docs/release-notes/release-notes-0.18.0.md

@@ -117,6 +117,11 @@
   in the rpc definition to ensure that the autogenerated API documentation
   properly specifies how to use the lncli command.
 
+* [Enable multiple outgoing channel ids for the payment
+  command](https://github.com/lightningnetwork/lnd/pull/8261). This change adds
+  the ability to specify multiple outgoing channel ids for the `sendpayment`
+  command.
+
 ## Code Health
 
 * [Remove Litecoin code](https://github.com/lightningnetwork/lnd/pull/7867).