Create python3 symlink on Windows

installers/win-setup-template.ps1

@@ -121,6 +121,11 @@ if ($LASTEXITCODE -ne 0) {
     Throw "Error happened during Python installation"
 }
 
+Write-Host "Create `python3` symlink"
+if ($MajorVersion -ne "2") {
+    New-Item -Path "$PythonArchPath\python3.exe" -ItemType SymbolicLink -Value "$PythonArchPath\python.exe"
+}
+
 Write-Host "Install and upgrade Pip"
 $PythonExePath = Join-Path -Path $PythonArchPath -ChildPath "python.exe"
 cmd.exe /c "$PythonExePath -m ensurepip && $PythonExePath -m pip install --upgrade pip --no-warn-script-location"