Add official portable Windows package for local installs

[S-S-X]

I guess this would basically be just 7zipping together single archive that contains all the stuff to allow installing game without admin rights.

So stuff from megalgles-data and this repo put together into new 7z archive that can be just extracted to directory and launched from there.

Of course if there's something in game that does attempt to write / read stuff outside of its install location / user directories then might need bit more work but probably there isn't such things?