Convenient installation packages

[tdammers]

To make deploying KES agents maximally easy/convenient, we should offer a selection of convenient, easy-to-use installation options, such as:

• Binary install tarball (download -> tar -xf -> ./install.sh)
• curl | sh (requires hosting binary installer tarball somewhere)
• Docker images
• Ready-to-use images for aarch64 (e.g. Raspberry Pi) and x86_64 Linux
• Nix
• Debian package (.deb; possibly hosting a source repo?)