Added Legendary and new packages types

Now we have Legendary as part of the application so it is not needed to download or install it again. But you still need xterm for now. I'm looking for a way to have a terminal inside the app as well.

I also built packages for Debian, a compressed file in tar.xz (just extract and run the heroic bin), and a Pacman package for Arch Linux.
I'll add an RPM package soon as well, but for now, just use the AppImage or extract the tar.xz file.