because path returned by Path() is .git/ and we need to move up two levels to update readme (since first path just removes trailing slash).

returned by Path() = /private/var/folders/gx/f2mcm5ls3cvd_d2xdq1cvvz40000gn/T/git2go477671622/.git/
Dir() = /private/var/folders/gx/f2mcm5ls3cvd_d2xdq1cvvz40000gn/T/git2go477671622/.git
Dir(Dir()) = /private/var/folders/gx/f2mcm5ls3cvd_d2xdq1cvvz40000gn/T/git2go477671622