Fix readme.txt file to conform to standards.

git-svn-id: https://plugins.svn.wordpress.org/gmo-ads-master/trunk@902128 b8457f37-d9ea-0310-8a92-e5e31aec5664
Fix readme.txt file to conform to standards.

git-svn-id: https://plugins.svn.wordpress.org/gmo-ads-master/trunk@902129 b8457f37-d9ea-0310-8a92-e5e31aec5664