feat(publish): Make installer portable.

[Coppertine]

I was unsure if this modpack installer is really requiring the user to install the modpack installer with admin privileges.
If possible, the exacutable could either allow you to either launch straight to the main screen without install or something similar.

[0ffz]

It should be really easy to add back a portable zipped executable, will do soon

[0ffz]

Ok just as an update, it's a little annoying because I need to package both exe installer and portable on one platform so I need to dig around configs and hop on Windows for a bit. I probably wont finish this as fast haha :p