Add resource grouping for prefixed apis to changelog

Author: Tim Vandecasteele

CHANGELOG.markdown

@@ -5,6 +5,7 @@
 * Adding hidden endpoints - [@arturoherrero](https://github.com/arturoherrero).
 * Fix: allow urls with `-` - [@dadario](https://github.com/dadario).
 * Fix: mounting multiple documentations - [@Drakula2k](https://github.com/Drakula2k).
+* Fix: resource groupings for prefixed APIs - [@aew](https://github.com/aew).
 * Your Contribution Here
 
 ### 0.6.0 (June 19, 2013)