modify design.md
modify design.md

ipdcode/containerfs,ipdcode/containerfs,shenhuichao/containerfs,shenhuichao/containerfs,ipdcode/containerfs,ipdcode/containerfs,zhengxiaochuan-3/containerfs,shenhuichao/containerfs,jls502/containerfs,shenhuichao/containerfs,shenhuichao/containerfs,ipdcode/containerfs,ipdcode/containerfs,ipdcode/containerfs,shenhuichao/containerfs,ipdcode/containerfs,ipdcode/containerfs,jls502/containerfs,shenhuichao/containerfs,shenhuichao/containerfs,shenhuichao/containerfs,zhengxiaochuan-3/containerfs