add documentation for update command
add documentation for update command

hw20686832/storm,emre/storm,emre/storm,neverware/storm,hw20686832/storm,mafrosis/storm2,emre/storm,neverware/storm,scalp42/storm,mafrosis/storm2,hw20686832/storm,scalp42/storm,neverware/storm,scalp42/storm,scalp42/storm,mafrosis/storm2,mafrosis/storm2,hw20686832/storm,emre/storm