readme.txt update

git-svn-id: https://plugins.svn.wordpress.org/amazon-product-in-a-post-plugin/trunk@1005285 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme.txt update 2

git-svn-id: https://plugins.svn.wordpress.org/amazon-product-in-a-post-plugin/trunk@1005290 b8457f37-d9ea-0310-8a92-e5e31aec5664