JS: change notes for improved support for Flow

change-notes/1.20/extractor-javascript.md

@@ -18,5 +18,6 @@
 
 ## Changes to code extraction
 
+* The extractor now supports additional [Flow](https://flow.org/) syntax.
 * The extractor now supports [Nullish Coalescing](https://github.com/tc39/proposal-nullish-coalescing) expressions.
 * The TypeScript extractor now handles the control-flow of logical operators and destructuring assignments more accurately.