Here's a config made by Pigloo that allows you to quickly bind a key to load any level in the game. To use it just drag this file into your base folder, then bind a key to the command "exec toggleil" to activate the config. To use it, just press F1 or F2 to cycle through the levels until you find the one you want, and it will bind F5 to load that level. You can change the binds by editing the config of course.