Added support for PolyMC and MultiMC. I still strongly recommend using Prism Launcher as the devs of these two launchers have done questionable things. The official launcher is also now supported. Support for flatpak versions is planned, but it might take a while.
In the script, replace [username] with your username and [instance name] with your Minecraft instance name (not in the official launcher)
REMEMBER TO BACK UP YOUR MODS BEFORE USING THIS