Toggle NERDTree without foucs on it is annoying

    Toggle NERDTree opening and foucs to it when we editing file and open
    NERDTree window when we opening a directory that will help us to navigate
    files faster.

    So we don't think toggle NERDTree open and lose foucs on it is such a good
    idea, and NERDTree should be opened by default when we opening a
    directory