Add changelog entry

Author: lorenzorapetti

CHANGELOG.md

@@ -15,6 +15,7 @@
 - `[jest-regex-util]`: Migrate to TypeScript ([#7822](https://github.com/facebook/jest/pull/7822))
 - `[jest-diff]`: Migrate to TypeScript ([#7824](https://github.com/facebook/jest/pull/7824))
 - `[jest-leak-detector]`: Migrate to TypeScript ([#7825](https://github.com/facebook/jest/pull/7825))
+- `[jest-changed-files]`: Migrate to TypeScript ([#7827](https://github.com/facebook/jest/pull/7827))
 
 ### Performance