Update changelog (#152)

Author: KonradStaniec

CHANGELOG.md

@@ -37,14 +37,16 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 ## Unreleased
 
+## v0.12.0
+
 ### State Machine Breaking
 
 * [#132](https://github.com/babylonlabs-io/babylon/pull/132) Add CosmWasm parameters
 update during v1 upgrade handler.
 * [#142](https://github.com/babylonlabs-io/babylon/pull/142) Remove signed finality providers
 insert from the v1 upgrade handler.
 
-### Misc Improvements
+### Improvements
 
 * [#130](https://github.com/babylonlabs-io/babylon/pull/130) Fix bugs in the
 transaction fee refunding mechanism for covenant signatures and finality signatures
@@ -56,9 +58,6 @@ pre-approval flow.
 messages inside `authz.MsgExec`.
 * [#146](https://github.com/babylonlabs-io/babylon/pull/146) Add property status as a filter
 to BTC delegations rest request `QueryBTCDelegationsRequest`.
-
-### Improvements
-
 * [#144](https://github.com/babylonlabs-io/babylon/pull/144) Add new finality provider events
 * [#131](https://github.com/babylonlabs-io/babylon/pull/131) Add new staking events
 * [#113](https://github.com/babylonlabs-io/babylon/pull/113) Add multibuild binary