Mention SO and Gitter for support

Author: PowerKiKi

README.md

@@ -18,12 +18,11 @@ PhpSpreadsheet is a library written in pure PHP and providing a set of classes t
 
 ## Documentation
 
-Read more about it, including install instructions, in the official documentation, either at the online version:
+Read more about it, including install instructions, in the official documentation:
 
 https://phpspreadsheet.readthedocs.io
 
-Or directly in this repository in the folder `docs/`.
-
+Please ask your support questions on [StackOverflow](http://stackoverflow.com/questions/tagged/phpspreadsheet), or have a quick chat on [Gitter](https://gitter.im/PHPOffice/PhpSpreadsheet).
 
 ## PHPExcel vs PhpSpreadsheet ?