update redeme, screenshots

git-svn-id: https://plugins.svn.wordpress.org/korea-sns/trunk@1011080 b8457f37-d9ea-0310-8a92-e5e31aec5664
update redeme

git-svn-id: https://plugins.svn.wordpress.org/korea-sns/trunk@1011081 b8457f37-d9ea-0310-8a92-e5e31aec5664