ts-web/core: add changelog

Author: pro-wh

client-sdk/ts-web/core/docs/changelog.md

@@ -2,6 +2,15 @@
 
 ## Unreleased changes
 
+Breaking changes:
+
+- `signature.NaclSigner` is moved out to a new
+  `@oasisprotocol/signer-tweetnacl` package.
+- `hdkey.HDKey.getAccountSigner` now returns a `signature.Signer` instead of
+  a tweetnacl `SignKeyPair`.
+  To get the private key, use the new `hdkey.HDKey.seedFromMnemonic` and
+  `hdkey.HDKey.privateKeyFromSeed` functions.
+
 New features:
 
 - Hashing and many related functions that internally need to compute a hash,
@@ -10,11 +19,19 @@ New features:
   We had implementations that used synchronous hashing libraries all along,
   but this is us giving up on eventually using the Web Crypto API for
   SHA-512/256.
+- For Ed25519 signing, there's a new `signature.WebCryptoSigner` taking the
+  place of `signature.NaclSigner`.
+  `await signature.WebCryptoSigner.generate(extractable)` is equivalent to
+  `signature.NaclSigner.fromRandom(note)`, and
+  `await signature.WebCryptoSigner.fromPrivateKey(priv)` is equivalent to
+  `signature.NaclSigner.fromSeed(priv, note)`.
 
 Little things:
 
+- Removed dependency on tweetnacl.
 - We're switching lots of cryptography dependencies to noble cryptography
   libraries.
+- Ed25519 verification now uses the Web Crypto API.
 
 ## v1.1.0