Appimage/Flatpak binaries for Linux

[CaptainMuskrat]

I would like to request the addition of Appimage and/or Flatpak support for Chocolate Duke 3D. As an intermediate Fedora user, it is oftentimes difficult to translate Ubuntu-centric instructions for my distro, and in order to make things easier for myself and for others, I would like to request an Appimage or Flatpak for the Chocolate Duke project. This would ensure cross-compatibility, as well.