docs: add changelog entry

Author: DannyvdSluijs

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Resolve deprecations of optional parameter ([#752](https://github.com/jsonrainbow/json-schema/pull/752))
 - Fix wrong combined paths when traversing upward, fixes #557 ([#652](https://github.com/jsonrainbow/json-schema/pull/652))
 - Correct PHPStan baseline ([#764](https://github.com/jsonrainbow/json-schema/pull/764))
+- Correct spacing issue in `README.md` ([#763](https://github.com/jsonrainbow/json-schema/pull/763))
 
 ### Changed
 - Bump to minimum PHP 7.2 ([#746](https://github.com/jsonrainbow/json-schema/pull/746))