Update README.md

Author: jwyg

README.md

@@ -1,9 +1,13 @@
 # zeehaven
 
-a tiny tool to convert [zeeschuimer](https://github.com/digitalmethodsinitiative/zeeschuimer) ndjson file into csv format.
+a tiny tool to convert [zeeschuimer](https://github.com/digitalmethodsinitiative/zeeschuimer) ndjson files into csv format.
 
 web interface available at: https://publicdatalab.github.io/zeehaven/
 
-developed by [iain](https://github.com/iaine/ndjson). themed by [jonathan](http://jonathangray.org/).
+if ndjson file is collected from instagram or twitter the tool structures the csv file accordingly, otherwise it outputs the whole ndjson file as a csv (which may contain many columns).
+
+if you encounter problems you can [add an issue](https://github.com/PublicDataLab/zeehaven/issues). 
 
 ![](img/screenshot.png)
+
+*developed by [iain](https://github.com/iaine/ndjson). themed by [jonathan](http://jonathangray.org/).*