Update README.markdown

Author: romainbossart

README.markdown

@@ -18,6 +18,9 @@ To enable code folding add the following to your `.vimrc`.
 
     au FileType javascript call JavaScriptFold()
 
+###Note
+This is a syntax plugin, not an indentation one. For indentation, you need to add another plugin
+(as mentioned [here](https://github.com/jelera/vim-javascript-syntax/issues/22#issuecomment-19917301)).
 
 ###TODO
 You can help me improve it too.