fixup! add musig module to change log

CHANGELOG.md

@@ -8,6 +8,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 #### Added
+ - New module `musig` implements the MuSig2 multisignature scheme according to the [BIP 327 specification](https://github.com/bitcoin/bips/blob/master/bip-0327.mediawiki). See:
+   - Header file `include/secp256k1_musig.h` which defines the new API.
+   - Document `doc/musig.md` for further notes on API usage.
+   - Usage example `examples/musig.c`.
  - Added `secp256k1_ec_pubkey_sort` which sorts an array of public keys (see `include/secp256k1.h`).
 
 ## [0.4.1] - 2023-12-21