Add README note about alternative to font patching

README.rst

@@ -3,3 +3,8 @@ Powerline fonts
 
 This repository contains pre-patched and adjusted fonts for usage with the 
 new Powerline plugin.
+
+**IMPORTANT:** If you're running Linux you may not have to use a patched 
+font! See the `Powerline font installation instructions 
+<http://lokaltog.github.com/powerline/overview.html#font-installation>`_ for 
+details.