updated documentation with fresh information

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1621537 13f79535-47bb-0310-9956-ffa450edef68
fixed typos

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1621538 13f79535-47bb-0310-9956-ffa450edef68