remove outdated note

Author: gjtorikian

README.md

@@ -1,8 +1,5 @@
 # HTML-Pipeline
 
-> **Note**
-> This README refers to the behavior in the new 3.0.0.pre gem.
-
 HTML processing filters and utilities. This module is a small
 framework for defining CSS-based content filters and applying them to user
 provided content.