portuguese translation

git-svn-id: https://plugins.svn.wordpress.org/jetpack-sharing/trunk@922888 b8457f37-d9ea-0310-8a92-e5e31aec5664
update readme

git-svn-id: https://plugins.svn.wordpress.org/jetpack-sharing/trunk@922889 b8457f37-d9ea-0310-8a92-e5e31aec5664