Add workaround to disable gzipping the server response for the app

README.md

@@ -7,6 +7,10 @@ An ownCloud app to work with office documents alone and/or collaboratively.
 
 [![Build Status](https://travis-ci.org/owncloud/documents.svg?branch=master)](https://travis-ci.org/owncloud/documents)
 
+### Known issues ###
+**Problem**: Editor doesn't open. Spinner spins for ages.  
+**Solution**: Try to disable gzip for Documents app by adding the following line to your .htaccess:  
+`SetEnvIf Request_URI .*/apps/documents/ajax/.* no-gzip dont-vary`
 
 ### How to add more fonts ###
 + Upload font files to **documents/css/fonts** directory