I made this simple Doom launcher. Hope you will like it!
Create directory like "C:/Games/Doom". Put exe file in it. Launch it and close. Three folders will appear. Put mods in mods, iwads in iwads and engine with all its files into engine/nameofengine(launcher can run only gzdoom and lzdoom). WARNING: MODS AND IWADS SHOULD HAVE NO SPACES IN THEIR NAMES! Now you can use this launcher.