CHANGELOG.md in sk_api_schema-0.9.0 vs CHANGELOG.md in sk_api_schema-0.9.1

@@ -1,9 +1,13 @@
 # SalesKing API Changelog
 
 See [commit messages](https://github.com/salesking/sk_api_schema/commits/) for details.
 Also sign up to our [Developer Newsletter](http://www.salesking.eu/dev/newsletter/) to stay up-to-date !!!
 
+##2014-01
+
+* filter documents by products (product_ids)
+
 ##2013-12
 
 * add cost_total, gross_margin to documents
 * rename product.cost_price to cost