updated readme

README.rst

@@ -2,6 +2,9 @@ logrotate
 =========
 Install and configure logrotate on a machine.
 
+The config files are per OS.
+At the moment only Debian, RedHat and Archlinux supported with this formula
+
 .. note::
     See the full `Salt Formulas installation and usage instructions
     <http://docs.saltstack.com/en/latest/topics/development/conventions/formulas.html>`_.