Update to (somewhat?) dendritic pattern

Heavily inspired by https://github.com/Doc-Steve/dendritic-design-with-flake-parts.

> Atomic commits? Never heard of them!

modules/system-settings/amd-gpu.nix

@@ -0,0 +1,18 @@
+{
+  flake.modules.nixos.amd-gpu = { pkgs, ... }: {
+    environment.systemPackages = with pkgs; [
+      rocmPackages.amdsmi
+    ];
+
+    boot.kernelModules = [ "kvm-amd" ];
+
+    hardware.graphics = {
+      enable = true;
+      extraPackages = [ pkgs.rocmPackages.clr.icd ];
+    };
+    hardware.amdgpu = {
+      initrd.enable = true;
+      opencl.enable = true;
+    };
+  };
+}