[MSKINS-72] Add copyright notice position option

git-svn-id: https://svn.apache.org/repos/asf/maven/skins/trunk@1428850 13f79535-47bb-0310-9956-ffa450edef68
[MSKINS-72] Add copyright notice position option
document option

git-svn-id: https://svn.apache.org/repos/asf/maven/skins/trunk@1428851 13f79535-47bb-0310-9956-ffa450edef68