docs: Add release notes for listwalletdir RPC

Author: promag

doc/release-notes-13152.md

@@ -1,4 +1,5 @@
 New RPC methods
 ------------
 
-- `getnodeaddresses` returns peer addresses known to this node. It may be used to connect to nodes over TCP without using the DNS seeds.
+- `getnodeaddresses` returns peer addresses known to this node. It may be used to connect to nodes over TCP without using the DNS seeds.
+- `listwalletdir` returns a list of wallets in the wallet directory which is configured with `-walletdir` parameter.