Add changelog entry

Author: mattphillips

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 ### Fixes
 
+- `[jest-each]` Template table heading validation and extraction ([#8766](https://github.com/facebook/jest/pull/8766))
 - `[jest-snapshot]` Inline snapshots: do not indent empty lines ([#8277](https://github.com/facebook/jest/pull/8277))
 - `[jest-core]` Make `detectOpenHandles` imply `runInBand` ([#8283](https://github.com/facebook/jest/pull/8283))