Minor change to readme.txt

git-svn-id: https://plugins.svn.wordpress.org/wp-symposium/trunk@806374 b8457f37-d9ea-0310-8a92-e5e31aec5664
Minor change to readme.txt

git-svn-id: https://plugins.svn.wordpress.org/wp-symposium/trunk@806375 b8457f37-d9ea-0310-8a92-e5e31aec5664