🐛  Fixed installation on windows #10890 (#12096)
🐛  Fixed installation on windows #10890 (#12096)

closes #10890

- use platform agnostic `exit 0` to allow `yarn setup` to work on windows
- requires powershell to be run as admin
bitjson/Ghost,ErisDS/Ghost,ErisDS/Ghost,janvt/Ghost,e10/Ghost,bitjson/Ghost,e10/Ghost,TryGhost/Ghost,TryGhost/Ghost,ErisDS/Ghost,TryGhost/Ghost,janvt/Ghost