docs: add release notes for multi-rfq send

Author: GeorgeTsagk

docs/release-notes/release-notes-0.7.0.md

@@ -47,6 +47,13 @@
   migration](https://github.com/lightninglabs/taproot-assets/pull/1612) was
   added that retroactively inserts all burned assets into that table.
 
+- Sending a payment now supports multi-rfq. This new feature allows for multiple
+  quotes to be used in order to carry out a payment. With multiple quotes, we
+  can use liquidity that is spread across different channels and also use
+  multiple rates. See
+  [related PR](https://github.com/lightninglabs/taproot-assets/pull/1613) for
+  more info.
+
 ## RPC Additions
 
 - The [price oracle RPC calls now have an intent, optional peer ID and metadata