added README

Author: robertmarsal

README.md

@@ -40,8 +40,11 @@ the page uri to identify a thread.
 
 The module comes with 2 themes for now. To implement new ones create a new partial view in `view/theme/yourtheme` using
 as base the existing ones.
+
 Use your new theme calling `$this->rbComment('yourtheme')`
 
+The current themes (and possible values of the `$theme` parameter) are :
+
 ##### default
 Basic theme with no external dependencies. Contains the minimum styling to make it look decent.