Add script to setup the PATH variable on Windows

setup-path-win.bat

@@ -0,0 +1,9 @@
+@echo off
+setx /M path "%PATH%;C:\MinGW\bin" > nul 2>&1
+if NOT ["%errorlevel%"]==["0"] (
+	echo FAILED. Rerun with administrator privileges.
+	pause
+) else (
+	echo Success!
+	pause
+)