Remove feed_summary plugin from list in ReadMe

Readme.rst

@@ -84,8 +84,6 @@ Events                    Add event start, duration, and location info to post m
 
 Extract table of content  Extracts table of contents (ToC) from ``article.content``
 
-Feed Summary              Allows article summaries to be used in ATOM and RSS feeds instead of the entire article
-
 Figure References         Provides a system to number and references figures
 
 Filetime from Git         Uses Git commit to determine page date