docs: add v2.3.0-provider-lsm section to CHANGELOG (#1432)

* add v2.3.0-provider-lsm section to CHANGELOG

* add unreleased section

Author: mpoke

CHANGELOG.md

@@ -1,9 +1,13 @@
 # CHANGELOG
 
-## [Unreleased]
+## Unreleased
 
 Add an entry to the unreleased section whenever merging a PR to main that is not targeted at a specific release. These entries will eventually be included in a release.
 
+## v2.3.0-provider-lsm
+
+*November 15, 2023*
+
 * (fix!) [#1422](https://github.com/cosmos/interchain-security/pull/1422) Fix the misbehaviour handling by verifying the signatures of byzantine validators.
 
 ## v2.2.0-provider-lsm