Remove readme.txt file

git-svn-id: https://plugins.svn.wordpress.org/microdata-manager/trunk@761561 b8457f37-d9ea-0310-8a92-e5e31aec5664
Updated readme.txt file

git-svn-id: https://plugins.svn.wordpress.org/microdata-manager/trunk@761562 b8457f37-d9ea-0310-8a92-e5e31aec5664