Fixed tar.md typo
Fixed tar.md typo

Small typo: arhive  to archive
claytonbrown/dokku,claytonbrown/dokku,claytonbrown/dokku,claytonbrown/dokku,dokku/dokku,dokku/dokku,dokku/dokku,dokku/dokku,claytonbrown/dokku,claytonbrown/dokku,claytonbrown/dokku,dokku/dokku,dokku/dokku,dokku/dokku,dokku/dokku,claytonbrown/dokku