removed screenshots from package

git-svn-id: https://plugins.svn.wordpress.org/awesome-flickr-gallery-plugin/trunk@912355 b8457f37-d9ea-0310-8a92-e5e31aec5664
updated readme

git-svn-id: https://plugins.svn.wordpress.org/awesome-flickr-gallery-plugin/trunk@912357 b8457f37-d9ea-0310-8a92-e5e31aec5664