docs: update CHANGELOG

Author: tkan145

CHANGELOG.md

@@ -7,6 +7,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Performance
+- Logging Policy: construct all templates at init time [PR #1587](https://github.com/3scale/APIcast/pull/1587)
+
 ### Fixed
 - Correct FAPI header to `x-fapi-interaction-id` [PR #1557](https://github.com/3scale/APIcast/pull/1557) [THREESCALE-11957](https://issues.redhat.com/browse/THREESCALE-11957)
 - Only validate oidc setting if authentication method is set to oidc [PR #1568](https://github.com/3scale/APIcast/pull/1568) [THREESCALE-11441](https://issues.redhat.com/browse/THREESCALE-11441)