Merge bitcoin-core/secp256k1#1177: Some improvements to the changelog

c30b889 Clarify that the ABI-incompatible versions are earlier (Pieter Wuille)
881fc33 Consistency in naming of modules (Pieter Wuille)
9ecf814 Reduce font size in changelog (Pieter Wuille)
2dc133a Add more changelog entries (Pieter Wuille)
ac233e1 Add links to diffs to changelog (Pieter Wuille)
cee8223 Mention semantic versioning in changelog (Pieter Wuille)

Pull request description:

ACKs for top commit:
  real-or-random:
    ACK c30b889
  jonasnick:
    ACK c30b889

Tree-SHA512: 0f753eae0ea4d65035bfbcd81b90169111ea030cf7196dd072fb1ccc8aac1437768031f3fcef431584028da68b66873204e16e03bcde4a6ae96b08ab7f97a480

CHANGELOG.md

@@ -1,28 +1,39 @@
 # Changelog
 
-The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
 
 ## [0.2.0] - 2022-12-12
 
-### Added
+#### Added
+ - Added usage examples for common use cases in a new `examples/` directory.
  - Added `secp256k1_selftest`, to be used in conjunction with `secp256k1_context_static`.
+ - Added support for 128-bit wide multiplication on MSVC for x86_64 and arm64, giving roughly a 20% speedup on those platforms.
 
-### Changed
- - Enabled modules schnorrsig, extrakeys and ECDH by default in `./configure`.
+#### Changed
+ - Enabled modules `schnorrsig`, `extrakeys` and `ecdh` by default in `./configure`.
+ - The `secp256k1_nonce_function_rfc6979` nonce function, used by default by `secp256k1_ecdsa_sign`, now reduces the message hash modulo the group order to match the specification. This only affects improper use of ECDSA signing API.
 
-### Deprecated
+#### Deprecated
  - Deprecated context flags `SECP256K1_CONTEXT_VERIFY` and `SECP256K1_CONTEXT_SIGN`. Use `SECP256K1_CONTEXT_NONE` instead.
  - Renamed `secp256k1_context_no_precomp` to `secp256k1_context_static`.
+ - Module `schnorrsig`: renamed `secp256k1_schnorrsig_sign` to `secp256k1_schnorrsig_sign32`.
 
-### ABI Compatibility
+#### ABI Compatibility
 
 Since this is the first release, we do not compare application binary interfaces.
-However, there are unreleased versions of libsecp256k1 that are *not* ABI compatible with this version.
+However, there are earlier unreleased versions of libsecp256k1 that are *not* ABI compatible with this version.
 
 ## [0.1.0] - 2013-03-05 to 2021-12-25
 
 This version was in fact never released.
 The number was given by the build system since the introduction of autotools in Jan 2014 (ea0fe5a5bf0c04f9cc955b2966b614f5f378c6f6).
 Therefore, this version number does not uniquely identify a set of source files.
+
+[unreleased]: https://github.com/bitcoin-core/secp256k1/compare/v0.2.0...HEAD
+[0.2.0]: https://github.com/bitcoin-core/secp256k1/compare/423b6d19d373f1224fd671a982584d7e7900bc93..v0.2.0
+[0.1.0]: https://github.com/bitcoin-core/secp256k1/commit/423b6d19d373f1224fd671a982584d7e7900bc93