Update README.md

Author: dminhhoang26

README.md

@@ -78,6 +78,7 @@ Overflow text
 - promise can add any value and return this value if not exec
 - TipTap headless editor (try to implement in angular)
 - Corepack for nodejs
+- Object.groupBy, Map.groupBy
 
 ### Libs
 - https://www.npmjs.com/package/ngx-image-cropper