Fix shell wrapper for PowerShell (#195)

This makes sure that `GetFullPath` gets evaluated before passing its
value to `Set-Location`. This prevents `Set-Location` from raising an
error "A positional parameter cannot be found that accepts argument
'C:\path\to\dir'".

docs/quick-start.md

@@ -91,7 +91,7 @@ function y {
     yazi $args --cwd-file="$tmp"
     $cwd = Get-Content -Path $tmp -Encoding UTF8
     if (-not [String]::IsNullOrEmpty($cwd) -and $cwd -ne $PWD.Path) {
-        Set-Location -LiteralPath [System.IO.Path]::GetFullPath($cwd)
+        Set-Location -LiteralPath ([System.IO.Path]::GetFullPath($cwd))
     }
     Remove-Item -Path $tmp
 }