Update CHANGELOG.md

Author: jeysal

CHANGELOG.md

@@ -14,6 +14,7 @@
 - `[jest-changed-files]` Improve default file selection for Mercurial repos ([#7880](https://github.com/facebook/jest/pull/7880))
 - `[jest-validate]` Fix validating async functions ([#7894](https://github.com/facebook/jest/issues/7894))
 - `[jest-circus]` Fix bug with test.only ([#7888](https://github.com/facebook/jest/pull/7888))
+- `[jest-config]` Use default cwd even if config contains a cwd property ([#7923](https://github.com/facebook/jest/pull/7923))
 
 ### Chore & Maintenance