since this project is still a work in progress, you have to build it from source.
if you use nix you can add this as a nix flake input
inputs = {
astrum.url = "github:vnuxa/astrum"
}
and somewhere in your package list add the following
astrum.defaultPackage.${pkgs.system}
I also recommend having the lua language server installed in your text editor, since it contains astrum types and descriptions