Add Windows one-command installer for contributors

install_windows.bat

@@ -0,0 +1,15 @@
+@echo off
+setlocal
+
+powershell -NoProfile -ExecutionPolicy Bypass -File "%~dp0install_windows.ps1" %*
+
+if errorlevel 1 (
+  echo.
+  echo Setup gagal. Baca pesan error di atas.
+  pause
+  exit /b 1
+)
+
+echo.
+echo Setup selesai.
+pause