docs: add changelog entry

docs/changelogs/v0.25.md

@@ -9,6 +9,7 @@
   - [RPC `API.Authorizations`](#rpc-apiauthorizations)
   - [MPLEX removal](#mplex-removal)
   - [Graphsync Experiment Removal](#graphsync-experiment-removal)
+  - [Commands `ipfs key sign` and `ipfs key verify`](#commands-ipfs-key-sign-and-ipfs-key-verify)
 - [📝 Changelog](#-changelog)
 - [👨‍👩‍👧‍👦 Contributors](#-contributors)
 
@@ -48,6 +49,17 @@ to update Kubo because some dependency changed and it fails to build anymore.
 
 For more information see https://github.com/ipfs/kubo/pull/9747.
 
+##### Commands `ipfs key sign` and `ipfs key verify`
+
+The Kubo CLI `ipfs key` now includes two new subcommands: `sign` and `verify`.
+This allows the Kubo node to sign arbitrary cryptographic bytes. For security,
+these will always be prefixed with `libp2p-key signed message:`.
+
+These commands are also both available through the RPC client and implemented
+in `client/rpc`.
+
+For more information see https://github.com/ipfs/kubo/issues/10230.
+
 ### 📝 Changelog
 
 ### 👨‍👩‍👧‍👦 Contributors